Vulnerabilities > CVE-2020-10967 - Improper Input Validation vulnerability in Dovecot

047910
CVSS 5.3 - MEDIUM
Attack vector
NETWORK
Attack complexity
LOW
Privileges required
NONE
Confidentiality impact
NONE
Integrity impact
NONE
Availability impact
LOW
network
low complexity
dovecot
CWE-20
nessus

Summary

In Dovecot before 2.3.10.1, remote unauthenticated attackers can crash the lmtp or submission process by sending mail with an empty localpart.

Vulnerable Configurations

Part Description Count
Application
Dovecot
244

Common Weakness Enumeration (CWE)

Common Attack Pattern Enumeration and Classification (CAPEC)

  • Buffer Overflow via Environment Variables
    This attack pattern involves causing a buffer overflow through manipulation of environment variables. Once the attacker finds that they can modify an environment variable, they may try to overflow associated buffers. This attack leverages implicit trust often placed in environment variables.
  • Server Side Include (SSI) Injection
    An attacker can use Server Side Include (SSI) Injection to send code to a web application that then gets executed by the web server. Doing so enables the attacker to achieve similar results to Cross Site Scripting, viz., arbitrary code execution and information disclosure, albeit on a more limited scale, since the SSI directives are nowhere near as powerful as a full-fledged scripting language. Nonetheless, the attacker can conveniently gain access to sensitive files, such as password files, and execute shell commands.
  • Cross Zone Scripting
    An attacker is able to cause a victim to load content into their web-browser that bypasses security zone controls and gain access to increased privileges to execute scripting code or other web objects such as unsigned ActiveX controls or applets. This is a privilege elevation attack targeted at zone-based web-browser security. In a zone-based model, pages belong to one of a set of zones corresponding to the level of privilege assigned to that page. Pages in an untrusted zone would have a lesser level of access to the system and/or be restricted in the types of executable content it was allowed to invoke. In a cross-zone scripting attack, a page that should be assigned to a less privileged zone is granted the privileges of a more trusted zone. This can be accomplished by exploiting bugs in the browser, exploiting incorrect configuration in the zone controls, through a cross-site scripting attack that causes the attackers' content to be treated as coming from a more trusted page, or by leveraging some piece of system functionality that is accessible from both the trusted and less trusted zone. This attack differs from "Restful Privilege Escalation" in that the latter correlates to the inadequate securing of RESTful access methods (such as HTTP DELETE) on the server, while cross-zone scripting attacks the concept of security zones as implemented by a browser.
  • Cross Site Scripting through Log Files
    An attacker may leverage a system weakness where logs are susceptible to log injection to insert scripts into the system's logs. If these logs are later viewed by an administrator through a thin administrative interface and the log data is not properly HTML encoded before being written to the page, the attackers' scripts stored in the log will be executed in the administrative interface with potentially serious consequences. This attack pattern is really a combination of two other attack patterns: log injection and stored cross site scripting.
  • Command Line Execution through SQL Injection
    An attacker uses standard SQL injection methods to inject data into the command line for execution. This could be done directly through misuse of directives such as MSSQL_xp_cmdshell or indirectly through injection of data into the database that would be interpreted as shell commands. Sometime later, an unscrupulous backend application (or could be part of the functionality of the same application) fetches the injected data stored in the database and uses this data as command line arguments without performing proper validation. The malicious data escapes that data plane by spawning new commands to be executed on the host.

Nessus

  • NASL familyUbuntu Local Security Checks
    NASL idUBUNTU_USN-4361-1.NASL
    descriptionPhilippe Antoine discovered that Dovecot incorrectly handled certain data. An attacker could possibly use this issue to cause a denial of service. (CVE-2020-10957, CVE-2020-10967) Philippe Antoine discovered that Dovecot incorrectly handled certain data. An attacker could possibly use this issue to cause a denial of service or execute arbitrary code. (CVE-2020-10958). Note that Tenable Network Security has extracted the preceding description block directly from the Ubuntu security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.
    last seen2020-05-31
    modified2020-05-19
    plugin id136708
    published2020-05-19
    reporterUbuntu Security Notice (C) 2020 Canonical, Inc. / NASL script (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/136708
    titleUbuntu 19.10 / 20.04 : dovecot vulnerabilities (USN-4361-1)
    code
    #
    # (C) Tenable Network Security, Inc.
    #
    # The descriptive text and package checks in this plugin were
    # extracted from Ubuntu Security Notice USN-4361-1. The text 
    # itself is copyright (C) Canonical, Inc. See 
    # <http://www.ubuntu.com/usn/>. Ubuntu(R) is a registered 
    # trademark of Canonical, Inc.
    #
    
    include("compat.inc");
    
    if (description)
    {
      script_id(136708);
      script_version("1.3");
      script_set_attribute(attribute:"plugin_modification_date", value:"2020/05/26");
    
      script_cve_id("CVE-2020-10957", "CVE-2020-10958", "CVE-2020-10967");
      script_xref(name:"USN", value:"4361-1");
    
      script_name(english:"Ubuntu 19.10 / 20.04 : dovecot vulnerabilities (USN-4361-1)");
      script_summary(english:"Checks dpkg output for updated package.");
    
      script_set_attribute(
        attribute:"synopsis",
        value:"The remote Ubuntu host is missing a security-related patch."
      );
      script_set_attribute(
        attribute:"description",
        value:
    "Philippe Antoine discovered that Dovecot incorrectly handled certain
    data. An attacker could possibly use this issue to cause a denial of
    service. (CVE-2020-10957, CVE-2020-10967)
    
    Philippe Antoine discovered that Dovecot incorrectly handled certain
    data. An attacker could possibly use this issue to cause a denial of
    service or execute arbitrary code. (CVE-2020-10958).
    
    Note that Tenable Network Security has extracted the preceding
    description block directly from the Ubuntu security advisory. Tenable
    has attempted to automatically clean and format it as much as possible
    without introducing additional issues."
      );
      script_set_attribute(
        attribute:"see_also",
        value:"https://usn.ubuntu.com/4361-1/"
      );
      script_set_attribute(
        attribute:"solution",
        value:"Update the affected dovecot-core package."
      );
      script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:P");
      script_set_cvss_temporal_vector("CVSS2#E:POC/RL:OF/RC:C");
      script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L");
      script_set_cvss3_temporal_vector("CVSS:3.0/E:P/RL:O/RC:C");
      script_set_attribute(attribute:"cvss_score_source", value:"CVE-2020-10967");
      script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
      script_set_attribute(attribute:"exploit_available", value:"true");
    
      script_set_attribute(attribute:"plugin_type", value:"local");
      script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:dovecot-core");
      script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:19.10");
      script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:20.04");
    
      script_set_attribute(attribute:"vuln_publication_date", value:"2020/05/18");
      script_set_attribute(attribute:"patch_publication_date", value:"2020/05/18");
      script_set_attribute(attribute:"plugin_publication_date", value:"2020/05/19");
      script_set_attribute(attribute:"generated_plugin", value:"current");
      script_end_attributes();
    
      script_category(ACT_GATHER_INFO);
      script_copyright(english:"Ubuntu Security Notice (C) 2020 Canonical, Inc. / NASL script (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof.");
      script_family(english:"Ubuntu Local Security Checks");
    
      script_dependencies("ssh_get_info.nasl");
      script_require_keys("Host/cpu", "Host/Ubuntu", "Host/Ubuntu/release", "Host/Debian/dpkg-l");
    
      exit(0);
    }
    
    
    include("audit.inc");
    include("ubuntu.inc");
    include("misc_func.inc");
    
    if ( ! get_kb_item("Host/local_checks_enabled") ) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
    release = get_kb_item("Host/Ubuntu/release");
    if ( isnull(release) ) audit(AUDIT_OS_NOT, "Ubuntu");
    release = chomp(release);
    if (! preg(pattern:"^(19\.10|20\.04)$", string:release)) audit(AUDIT_OS_NOT, "Ubuntu 19.10 / 20.04", "Ubuntu " + release);
    if ( ! get_kb_item("Host/Debian/dpkg-l") ) audit(AUDIT_PACKAGE_LIST_MISSING);
    
    cpu = get_kb_item("Host/cpu");
    if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH);
    if ("x86_64" >!< cpu && cpu !~ "^i[3-6]86$") audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, "Ubuntu", cpu);
    
    flag = 0;
    
    if (ubuntu_check(osver:"19.10", pkgname:"dovecot-core", pkgver:"1:2.3.4.1-5ubuntu3.1")) flag++;
    if (ubuntu_check(osver:"20.04", pkgname:"dovecot-core", pkgver:"1:2.3.7.2-1ubuntu3.1")) flag++;
    
    if (flag)
    {
      security_report_v4(
        port       : 0,
        severity   : SECURITY_WARNING,
        extra      : ubuntu_report_get()
      );
      exit(0);
    }
    else
    {
      tested = ubuntu_pkg_tests_get();
      if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
      else audit(AUDIT_PACKAGE_NOT_INSTALLED, "dovecot-core");
    }
    
  • NASL familyFedora Local Security Checks
    NASL idFEDORA_2020-B60344C987.NASL
    description - CVE-2020-10957: lmtp/submission: A client can crash the server by sending a NOOP command with an invalid string parameter. This occurs particularly for a parameter that doesn
    last seen2020-06-06
    modified2020-05-28
    plugin id136938
    published2020-05-28
    reporterThis script is Copyright (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/136938
    titleFedora 31 : 1:dovecot (2020-b60344c987)
    code
    #
    # (C) Tenable Network Security, Inc.
    #
    # The descriptive text and package checks in this plugin were  
    # extracted from Fedora Security Advisory FEDORA-2020-b60344c987.
    #
    
    include("compat.inc");
    
    if (description)
    {
      script_id(136938);
      script_version("1.2");
      script_set_attribute(attribute:"plugin_modification_date", value:"2020/06/05");
    
      script_cve_id("CVE-2020-10957", "CVE-2020-10958", "CVE-2020-10967");
      script_xref(name:"FEDORA", value:"2020-b60344c987");
    
      script_name(english:"Fedora 31 : 1:dovecot (2020-b60344c987)");
      script_summary(english:"Checks rpm output for the updated package.");
    
      script_set_attribute(
        attribute:"synopsis",
        value:"The remote Fedora host is missing a security update."
      );
      script_set_attribute(
        attribute:"description",
        value:
    "  - CVE-2020-10957: lmtp/submission: A client can crash the
        server by sending a NOOP command with an invalid string
        parameter. This occurs particularly for a parameter that
        doesn't start with a double quote. This applies to all
        SMTP services, including submission-login, which makes
        it possible to crash the submission service without
        authentication.
    
      - CVE-2020-10958: lmtp/submission: Sending many invalid or
        unknown commands can cause the server to access freed
        memory, which can lead to a server crash. This happens
        when the server closes the connection with a '421 Too
        many invalid commands' error. The bad command limit
        depends on the service (lmtp or submission) and varies
        between 10 to 20 bad commands.
    
      - CVE-2020-10967: lmtp/submission: Issuing the RCPT
        command with an address that has the empty quoted string
        as local-part causes the lmtp service to crash.
    
    Note that Tenable Network Security has extracted the preceding
    description block directly from the Fedora update system website.
    Tenable has attempted to automatically clean and format it as much as
    possible without introducing additional issues."
      );
      script_set_attribute(
        attribute:"see_also",
        value:"https://bodhi.fedoraproject.org/updates/FEDORA-2020-b60344c987"
      );
      script_set_attribute(
        attribute:"solution",
        value:"Update the affected 1:dovecot package."
      );
      script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:P");
      script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
      script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L");
      script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
      script_set_attribute(attribute:"cvss_score_source", value:"CVE-2020-10967");
      script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
      script_set_attribute(attribute:"exploit_available", value:"true");
    
      script_set_attribute(attribute:"plugin_type", value:"local");
      script_set_attribute(attribute:"cpe", value:"p-cpe:/a:fedoraproject:fedora:1:dovecot");
      script_set_attribute(attribute:"cpe", value:"cpe:/o:fedoraproject:fedora:31");
    
      script_set_attribute(attribute:"vuln_publication_date", value:"2020/05/18");
      script_set_attribute(attribute:"patch_publication_date", value:"2020/05/28");
      script_set_attribute(attribute:"plugin_publication_date", value:"2020/05/28");
      script_set_attribute(attribute:"generated_plugin", value:"current");
      script_end_attributes();
    
      script_category(ACT_GATHER_INFO);
      script_copyright(english:"This script is Copyright (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof.");
      script_family(english:"Fedora Local Security Checks");
    
      script_dependencies("ssh_get_info.nasl");
      script_require_keys("Host/local_checks_enabled", "Host/RedHat/release", "Host/RedHat/rpm-list");
    
      exit(0);
    }
    
    
    include("audit.inc");
    include("global_settings.inc");
    include("rpm.inc");
    
    
    if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
    release = get_kb_item("Host/RedHat/release");
    if (isnull(release) || "Fedora" >!< release) audit(AUDIT_OS_NOT, "Fedora");
    os_ver = pregmatch(pattern: "Fedora.*release ([0-9]+)", string:release);
    if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, "Fedora");
    os_ver = os_ver[1];
    if (! preg(pattern:"^31([^0-9]|$)", string:os_ver)) audit(AUDIT_OS_NOT, "Fedora 31", "Fedora " + os_ver);
    
    if (!get_kb_item("Host/RedHat/rpm-list")) audit(AUDIT_PACKAGE_LIST_MISSING);
    
    
    cpu = get_kb_item("Host/cpu");
    if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH);
    if ("x86_64" >!< cpu && cpu !~ "^i[3-6]86$") audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, "Fedora", cpu);
    
    
    flag = 0;
    if (rpm_check(release:"FC31", reference:"dovecot-2.3.10.1-1.fc31", epoch:"1")) flag++;
    
    
    if (flag)
    {
      security_report_v4(
        port       : 0,
        severity   : SECURITY_WARNING,
        extra      : rpm_report_get()
      );
      exit(0);
    }
    else
    {
      tested = pkg_tests_get();
      if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
      else audit(AUDIT_PACKAGE_NOT_INSTALLED, "1:dovecot");
    }
    
  • NASL familyFreeBSD Local Security Checks
    NASL idFREEBSD_PKG_37D106A815A4483E8247FCB68B16EAF8.NASL
    descriptionAki Tuomi reports : Vulnerability Details : Sending malformed NOOP command causes crash in submission, submission-login or lmtp service. Risk : Remote attacker can keep submission-login service down, causing denial of service attack. For lmtp the risk is neglible, as lmtp is usually behind a trusted MTA. Steps to reproduce : Send ``NOOP EE
    last seen2020-05-31
    modified2020-05-19
    plugin id136706
    published2020-05-19
    reporterThis script is Copyright (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/136706
    titleFreeBSD : Dovecot -- Multiple vulnerabilities (37d106a8-15a4-483e-8247-fcb68b16eaf8)
    code
    #
    # (C) Tenable Network Security, Inc.
    #
    # The descriptive text and package checks in this plugin were  
    # extracted from the FreeBSD VuXML database :
    #
    # Copyright 2003-2020 Jacques Vidrine and contributors
    #
    # Redistribution and use in source (VuXML) and 'compiled' forms (SGML,
    # HTML, PDF, PostScript, RTF and so forth) with or without modification,
    # are permitted provided that the following conditions are met:
    # 1. Redistributions of source code (VuXML) must retain the above
    #    copyright notice, this list of conditions and the following
    #    disclaimer as the first lines of this file unmodified.
    # 2. Redistributions in compiled form (transformed to other DTDs,
    #    published online in any format, converted to PDF, PostScript,
    #    RTF and other formats) must reproduce the above copyright
    #    notice, this list of conditions and the following disclaimer
    #    in the documentation and/or other materials provided with the
    #    distribution.
    # 
    # THIS DOCUMENTATION IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS "AS IS"
    # AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
    # THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
    # PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS
    # BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
    # OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
    # OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
    # BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
    # WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
    # OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS DOCUMENTATION,
    # EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
    #
    
    include("compat.inc");
    
    if (description)
    {
      script_id(136706);
      script_version("1.3");
      script_set_attribute(attribute:"plugin_modification_date", value:"2020/05/26");
    
      script_cve_id("CVE-2020-10957", "CVE-2020-10958", "CVE-2020-10967");
    
      script_name(english:"FreeBSD : Dovecot -- Multiple vulnerabilities (37d106a8-15a4-483e-8247-fcb68b16eaf8)");
      script_summary(english:"Checks for updated package in pkg_info output");
    
      script_set_attribute(
        attribute:"synopsis",
        value:"The remote FreeBSD host is missing a security-related update."
      );
      script_set_attribute(
        attribute:"description",
        value:
    "Aki Tuomi reports :
    
    Vulnerability Details : Sending malformed NOOP command causes crash in
    submission, submission-login or lmtp service.
    
    Risk : Remote attacker can keep submission-login service down, causing
    denial of service attack. For lmtp the risk is neglible, as lmtp is
    usually behind a trusted MTA.
    
    Steps to reproduce : Send ``NOOP EE'FY`` to submission port, or
    similarly malformed command.
    
    Vulnerability Details :
    
    Sending command followed by sufficient number of newlines triggers a
    use-after-free bug that might crash submission-login, submission or
    lmtp service.
    
    Risk :
    
    Remote attacker can keep submission-login service down, causing denial
    of service attack. For lmtp the risk is neglible, as lmtp is usually
    behind a trusted MTA.
    
    Steps to reproduce :
    
    This can be currently reproduced with ASAN or Valgrind. Reliable way
    to crash has not yet been discovered.
    
    Vulnerability Details : Sending mail with empty quoted localpart
    causes submission or lmtp component to crash.
    
    Risk : Malicious actor can cause denial of service to mail delivery by
    repeatedly sending mails with bad sender or recipient address.
    
    Steps to reproduce : Send mail with envelope sender or recipient as
    <''@example.org>.
    
    Workaround : For submission there is no workaround, but triggering the
    bug requires valid credentials. For lmtp, one can implement sufficient
    filtering on MTA level to prevent mails with such addresses from
    ending up in LMTP delivery."
      );
      script_set_attribute(
        attribute:"see_also",
        value:"https://dovecot.org/pipermail/dovecot-news/2020-May/000438.html"
      );
      # https://vuxml.freebsd.org/freebsd/37d106a8-15a4-483e-8247-fcb68b16eaf8.html
      script_set_attribute(
        attribute:"see_also",
        value:"http://www.nessus.org/u?3f67388d"
      );
      script_set_attribute(attribute:"solution", value:"Update the affected package.");
      script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:P");
      script_set_cvss_temporal_vector("CVSS2#E:POC/RL:OF/RC:C");
      script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L");
      script_set_cvss3_temporal_vector("CVSS:3.0/E:P/RL:O/RC:C");
      script_set_attribute(attribute:"cvss_score_source", value:"CVE-2020-10967");
      script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
      script_set_attribute(attribute:"exploit_available", value:"true");
    
      script_set_attribute(attribute:"plugin_type", value:"local");
      script_set_attribute(attribute:"cpe", value:"p-cpe:/a:freebsd:freebsd:dovecot");
      script_set_attribute(attribute:"cpe", value:"cpe:/o:freebsd:freebsd");
    
      script_set_attribute(attribute:"vuln_publication_date", value:"2020/04/02");
      script_set_attribute(attribute:"patch_publication_date", value:"2020/05/18");
      script_set_attribute(attribute:"plugin_publication_date", value:"2020/05/19");
      script_set_attribute(attribute:"generated_plugin", value:"current");
      script_end_attributes();
    
      script_category(ACT_GATHER_INFO);
      script_copyright(english:"This script is Copyright (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof.");
      script_family(english:"FreeBSD Local Security Checks");
    
      script_dependencies("ssh_get_info.nasl");
      script_require_keys("Host/local_checks_enabled", "Host/FreeBSD/release", "Host/FreeBSD/pkg_info");
    
      exit(0);
    }
    
    
    include("audit.inc");
    include("freebsd_package.inc");
    
    
    if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
    if (!get_kb_item("Host/FreeBSD/release")) audit(AUDIT_OS_NOT, "FreeBSD");
    if (!get_kb_item("Host/FreeBSD/pkg_info")) audit(AUDIT_PACKAGE_LIST_MISSING);
    
    
    flag = 0;
    
    if (pkg_test(save_report:TRUE, pkg:"dovecot<2.3.10.1")) flag++;
    
    if (flag)
    {
      if (report_verbosity > 0) security_warning(port:0, extra:pkg_report_get());
      else security_warning(0);
      exit(0);
    }
    else audit(AUDIT_HOST_NOT, "affected");
    
  • NASL familySuSE Local Security Checks
    NASL idOPENSUSE-2020-720.NASL
    descriptionThis update for dovecot23 to 2.3.10 fixes the following issues : Security issues fixed : - CVE-2020-10957: Fixed a crash caused by malformed NOOP commands (bsc#1171457). - CVE-2020-10958: Fixed a use-after-free when receiving too many newlines (bsc#1171458). - CVE-2020-10967: Fixed a crash in the lmtp and submission components caused by mails with empty quoted localparts (bsc#1171456). Non-security issues fixed : - The update to 2.3.10 fixes several bugs. Please refer to https://dovecot.org/doc/NEWS for a complete list of changes. This update was imported from the SUSE:SLE-15-SP1:Update update project.
    last seen2020-06-06
    modified2020-05-29
    plugin id136961
    published2020-05-29
    reporterThis script is Copyright (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/136961
    titleopenSUSE Security Update : dovecot23 (openSUSE-2020-720)
    code
    #
    # (C) Tenable Network Security, Inc.
    #
    # The descriptive text and package checks in this plugin were
    # extracted from openSUSE Security Update openSUSE-2020-720.
    #
    # The text description of this plugin is (C) SUSE LLC.
    #
    
    include("compat.inc");
    
    if (description)
    {
      script_id(136961);
      script_version("1.2");
      script_set_attribute(attribute:"plugin_modification_date", value:"2020/06/05");
    
      script_cve_id("CVE-2020-10957", "CVE-2020-10958", "CVE-2020-10967");
    
      script_name(english:"openSUSE Security Update : dovecot23 (openSUSE-2020-720)");
      script_summary(english:"Check for the openSUSE-2020-720 patch");
    
      script_set_attribute(
        attribute:"synopsis",
        value:"The remote openSUSE host is missing a security update."
      );
      script_set_attribute(
        attribute:"description",
        value:
    "This update for dovecot23 to 2.3.10 fixes the following issues :
    
    Security issues fixed :
    
      - CVE-2020-10957: Fixed a crash caused by malformed NOOP
        commands (bsc#1171457).
    
      - CVE-2020-10958: Fixed a use-after-free when receiving
        too many newlines (bsc#1171458).
    
      - CVE-2020-10967: Fixed a crash in the lmtp and submission
        components caused by mails with empty quoted localparts
        (bsc#1171456).
    
    Non-security issues fixed :
    
      - The update to 2.3.10 fixes several bugs. Please refer to
        https://dovecot.org/doc/NEWS for a complete list of
        changes.
    
    This update was imported from the SUSE:SLE-15-SP1:Update update
    project."
      );
      script_set_attribute(
        attribute:"see_also",
        value:"https://bugzilla.opensuse.org/show_bug.cgi?id=1171456"
      );
      script_set_attribute(
        attribute:"see_also",
        value:"https://bugzilla.opensuse.org/show_bug.cgi?id=1171457"
      );
      script_set_attribute(
        attribute:"see_also",
        value:"https://bugzilla.opensuse.org/show_bug.cgi?id=1171458"
      );
      script_set_attribute(
        attribute:"see_also",
        value:"https://dovecot.org/doc/NEWS"
      );
      script_set_attribute(
        attribute:"solution",
        value:"Update the affected dovecot23 packages."
      );
      script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:P");
      script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
      script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L");
      script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
      script_set_attribute(attribute:"cvss_score_source", value:"CVE-2020-10967");
      script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
      script_set_attribute(attribute:"exploit_available", value:"true");
    
      script_set_attribute(attribute:"plugin_type", value:"local");
      script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:dovecot23");
      script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:dovecot23-backend-mysql");
      script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:dovecot23-backend-mysql-debuginfo");
      script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:dovecot23-backend-pgsql");
      script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:dovecot23-backend-pgsql-debuginfo");
      script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:dovecot23-backend-sqlite");
      script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:dovecot23-backend-sqlite-debuginfo");
      script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:dovecot23-debuginfo");
      script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:dovecot23-debugsource");
      script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:dovecot23-devel");
      script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:dovecot23-fts");
      script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:dovecot23-fts-debuginfo");
      script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:dovecot23-fts-lucene");
      script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:dovecot23-fts-lucene-debuginfo");
      script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:dovecot23-fts-solr");
      script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:dovecot23-fts-solr-debuginfo");
      script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:dovecot23-fts-squat");
      script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:dovecot23-fts-squat-debuginfo");
      script_set_attribute(attribute:"cpe", value:"cpe:/o:novell:opensuse:15.1");
    
      script_set_attribute(attribute:"vuln_publication_date", value:"2020/05/18");
      script_set_attribute(attribute:"patch_publication_date", value:"2020/05/26");
      script_set_attribute(attribute:"plugin_publication_date", value:"2020/05/29");
      script_set_attribute(attribute:"generated_plugin", value:"current");
      script_end_attributes();
    
      script_category(ACT_GATHER_INFO);
      script_copyright(english:"This script is Copyright (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof.");
      script_family(english:"SuSE Local Security Checks");
    
      script_dependencies("ssh_get_info.nasl");
      script_require_keys("Host/local_checks_enabled", "Host/SuSE/release", "Host/SuSE/rpm-list", "Host/cpu");
    
      exit(0);
    }
    
    
    include("audit.inc");
    include("global_settings.inc");
    include("rpm.inc");
    
    if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
    release = get_kb_item("Host/SuSE/release");
    if (isnull(release) || release =~ "^(SLED|SLES)") audit(AUDIT_OS_NOT, "openSUSE");
    if (release !~ "^(SUSE15\.1)$") audit(AUDIT_OS_RELEASE_NOT, "openSUSE", "15.1", release);
    if (!get_kb_item("Host/SuSE/rpm-list")) audit(AUDIT_PACKAGE_LIST_MISSING);
    
    ourarch = get_kb_item("Host/cpu");
    if (!ourarch) audit(AUDIT_UNKNOWN_ARCH);
    if (ourarch !~ "^(x86_64)$") audit(AUDIT_ARCH_NOT, "x86_64", ourarch);
    
    flag = 0;
    
    if ( rpm_check(release:"SUSE15.1", reference:"dovecot23-2.3.10-lp151.2.9.1") ) flag++;
    if ( rpm_check(release:"SUSE15.1", reference:"dovecot23-backend-mysql-2.3.10-lp151.2.9.1") ) flag++;
    if ( rpm_check(release:"SUSE15.1", reference:"dovecot23-backend-mysql-debuginfo-2.3.10-lp151.2.9.1") ) flag++;
    if ( rpm_check(release:"SUSE15.1", reference:"dovecot23-backend-pgsql-2.3.10-lp151.2.9.1") ) flag++;
    if ( rpm_check(release:"SUSE15.1", reference:"dovecot23-backend-pgsql-debuginfo-2.3.10-lp151.2.9.1") ) flag++;
    if ( rpm_check(release:"SUSE15.1", reference:"dovecot23-backend-sqlite-2.3.10-lp151.2.9.1") ) flag++;
    if ( rpm_check(release:"SUSE15.1", reference:"dovecot23-backend-sqlite-debuginfo-2.3.10-lp151.2.9.1") ) flag++;
    if ( rpm_check(release:"SUSE15.1", reference:"dovecot23-debuginfo-2.3.10-lp151.2.9.1") ) flag++;
    if ( rpm_check(release:"SUSE15.1", reference:"dovecot23-debugsource-2.3.10-lp151.2.9.1") ) flag++;
    if ( rpm_check(release:"SUSE15.1", reference:"dovecot23-devel-2.3.10-lp151.2.9.1") ) flag++;
    if ( rpm_check(release:"SUSE15.1", reference:"dovecot23-fts-2.3.10-lp151.2.9.1") ) flag++;
    if ( rpm_check(release:"SUSE15.1", reference:"dovecot23-fts-debuginfo-2.3.10-lp151.2.9.1") ) flag++;
    if ( rpm_check(release:"SUSE15.1", reference:"dovecot23-fts-lucene-2.3.10-lp151.2.9.1") ) flag++;
    if ( rpm_check(release:"SUSE15.1", reference:"dovecot23-fts-lucene-debuginfo-2.3.10-lp151.2.9.1") ) flag++;
    if ( rpm_check(release:"SUSE15.1", reference:"dovecot23-fts-solr-2.3.10-lp151.2.9.1") ) flag++;
    if ( rpm_check(release:"SUSE15.1", reference:"dovecot23-fts-solr-debuginfo-2.3.10-lp151.2.9.1") ) flag++;
    if ( rpm_check(release:"SUSE15.1", reference:"dovecot23-fts-squat-2.3.10-lp151.2.9.1") ) flag++;
    if ( rpm_check(release:"SUSE15.1", reference:"dovecot23-fts-squat-debuginfo-2.3.10-lp151.2.9.1") ) flag++;
    
    if (flag)
    {
      if (report_verbosity > 0) security_warning(port:0, extra:rpm_report_get());
      else security_warning(0);
      exit(0);
    }
    else
    {
      tested = pkg_tests_get();
      if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
      else audit(AUDIT_PACKAGE_NOT_INSTALLED, "dovecot23 / dovecot23-backend-mysql / etc");
    }
    
  • NASL familyFedora Local Security Checks
    NASL idFEDORA_2020-1DEE17D880.NASL
    description - CVE-2020-10957: lmtp/submission: A client can crash the server by sending a NOOP command with an invalid string parameter. This occurs particularly for a parameter that doesn
    last seen2020-06-10
    modified2020-06-04
    plugin id137106
    published2020-06-04
    reporterThis script is Copyright (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/137106
    titleFedora 32 : 1:dovecot (2020-1dee17d880)
    code
    #
    # (C) Tenable Network Security, Inc.
    #
    # The descriptive text and package checks in this plugin were  
    # extracted from Fedora Security Advisory FEDORA-2020-1dee17d880.
    #
    
    include("compat.inc");
    
    if (description)
    {
      script_id(137106);
      script_version("1.2");
      script_set_attribute(attribute:"plugin_modification_date", value:"2020/06/09");
    
      script_cve_id("CVE-2020-10957", "CVE-2020-10958", "CVE-2020-10967");
      script_xref(name:"FEDORA", value:"2020-1dee17d880");
    
      script_name(english:"Fedora 32 : 1:dovecot (2020-1dee17d880)");
      script_summary(english:"Checks rpm output for the updated package.");
    
      script_set_attribute(
        attribute:"synopsis",
        value:"The remote Fedora host is missing a security update."
      );
      script_set_attribute(
        attribute:"description",
        value:
    "  - CVE-2020-10957: lmtp/submission: A client can crash the
        server by sending a NOOP command with an invalid string
        parameter. This occurs particularly for a parameter that
        doesn't start with a double quote. This applies to all
        SMTP services, including submission-login, which makes
        it possible to crash the submission service without
        authentication.
    
      - CVE-2020-10958: lmtp/submission: Sending many invalid or
        unknown commands can cause the server to access freed
        memory, which can lead to a server crash. This happens
        when the server closes the connection with a '421 Too
        many invalid commands' error. The bad command limit
        depends on the service (lmtp or submission) and varies
        between 10 to 20 bad commands.
    
      - CVE-2020-10967: lmtp/submission: Issuing the RCPT
        command with an address that has the empty quoted string
        as local-part causes the lmtp service to crash.
    
    ----
    
    dovecot updated to 2.3.10
    
    Note that Tenable Network Security has extracted the preceding
    description block directly from the Fedora update system website.
    Tenable has attempted to automatically clean and format it as much as
    possible without introducing additional issues."
      );
      script_set_attribute(
        attribute:"see_also",
        value:"https://bodhi.fedoraproject.org/updates/FEDORA-2020-1dee17d880"
      );
      script_set_attribute(
        attribute:"solution",
        value:"Update the affected 1:dovecot package."
      );
      script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:P");
      script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
      script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L");
      script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
      script_set_attribute(attribute:"cvss_score_source", value:"CVE-2020-10967");
      script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
      script_set_attribute(attribute:"exploit_available", value:"true");
    
      script_set_attribute(attribute:"plugin_type", value:"local");
      script_set_attribute(attribute:"cpe", value:"p-cpe:/a:fedoraproject:fedora:1:dovecot");
      script_set_attribute(attribute:"cpe", value:"cpe:/o:fedoraproject:fedora:32");
    
      script_set_attribute(attribute:"vuln_publication_date", value:"2020/05/18");
      script_set_attribute(attribute:"patch_publication_date", value:"2020/05/24");
      script_set_attribute(attribute:"plugin_publication_date", value:"2020/06/04");
      script_set_attribute(attribute:"generated_plugin", value:"current");
      script_end_attributes();
    
      script_category(ACT_GATHER_INFO);
      script_copyright(english:"This script is Copyright (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof.");
      script_family(english:"Fedora Local Security Checks");
    
      script_dependencies("ssh_get_info.nasl");
      script_require_keys("Host/local_checks_enabled", "Host/RedHat/release", "Host/RedHat/rpm-list");
    
      exit(0);
    }
    
    
    include("audit.inc");
    include("global_settings.inc");
    include("rpm.inc");
    
    
    if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
    release = get_kb_item("Host/RedHat/release");
    if (isnull(release) || "Fedora" >!< release) audit(AUDIT_OS_NOT, "Fedora");
    os_ver = pregmatch(pattern: "Fedora.*release ([0-9]+)", string:release);
    if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, "Fedora");
    os_ver = os_ver[1];
    if (! preg(pattern:"^32([^0-9]|$)", string:os_ver)) audit(AUDIT_OS_NOT, "Fedora 32", "Fedora " + os_ver);
    
    if (!get_kb_item("Host/RedHat/rpm-list")) audit(AUDIT_PACKAGE_LIST_MISSING);
    
    
    cpu = get_kb_item("Host/cpu");
    if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH);
    if ("x86_64" >!< cpu && cpu !~ "^i[3-6]86$") audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, "Fedora", cpu);
    
    
    flag = 0;
    if (rpm_check(release:"FC32", reference:"dovecot-2.3.10.1-1.fc32", epoch:"1")) flag++;
    
    
    if (flag)
    {
      security_report_v4(
        port       : 0,
        severity   : SECURITY_WARNING,
        extra      : rpm_report_get()
      );
      exit(0);
    }
    else
    {
      tested = pkg_tests_get();
      if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
      else audit(AUDIT_PACKAGE_NOT_INSTALLED, "1:dovecot");
    }
    
  • NASL familyDebian Local Security Checks
    NASL idDEBIAN_DSA-4690.NASL
    descriptionSeveral vulnerabilities were discovered in the Dovecot email server, which could cause crashes in the submission, submission-login or lmtp services, resulting in denial of service.
    last seen2020-05-31
    modified2020-05-21
    plugin id136754
    published2020-05-21
    reporterThis script is Copyright (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/136754
    titleDebian DSA-4690-1 : dovecot - security update
    code
    #
    # (C) Tenable Network Security, Inc.
    #
    # The descriptive text and package checks in this plugin were  
    # extracted from Debian Security Advisory DSA-4690. The text 
    # itself is copyright (C) Software in the Public Interest, Inc.
    #
    
    include("compat.inc");
    
    if (description)
    {
      script_id(136754);
      script_version("1.2");
      script_set_attribute(attribute:"plugin_modification_date", value:"2020/05/26");
    
      script_cve_id("CVE-2020-10957", "CVE-2020-10958", "CVE-2020-10967");
      script_xref(name:"DSA", value:"4690");
    
      script_name(english:"Debian DSA-4690-1 : dovecot - security update");
      script_summary(english:"Checks dpkg output for the updated package");
    
      script_set_attribute(
        attribute:"synopsis",
        value:"The remote Debian host is missing a security-related update."
      );
      script_set_attribute(
        attribute:"description",
        value:
    "Several vulnerabilities were discovered in the Dovecot email server,
    which could cause crashes in the submission, submission-login or lmtp
    services, resulting in denial of service."
      );
      script_set_attribute(
        attribute:"see_also",
        value:"https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=960963"
      );
      script_set_attribute(
        attribute:"see_also",
        value:"https://security-tracker.debian.org/tracker/source-package/dovecot"
      );
      script_set_attribute(
        attribute:"see_also",
        value:"https://packages.debian.org/source/buster/dovecot"
      );
      script_set_attribute(
        attribute:"see_also",
        value:"https://www.debian.org/security/2020/dsa-4690"
      );
      script_set_attribute(
        attribute:"solution",
        value:
    "Upgrade the dovecot packages.
    
    For the stable distribution (buster), these problems have been fixed
    in version 1:2.3.4.1-5+deb10u2."
      );
      script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:P");
      script_set_cvss_temporal_vector("CVSS2#E:POC/RL:OF/RC:C");
      script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L");
      script_set_cvss3_temporal_vector("CVSS:3.0/E:P/RL:O/RC:C");
      script_set_attribute(attribute:"cvss_score_source", value:"CVE-2020-10967");
      script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
      script_set_attribute(attribute:"exploit_available", value:"true");
    
      script_set_attribute(attribute:"plugin_type", value:"local");
      script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:dovecot");
      script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:10.0");
    
      script_set_attribute(attribute:"vuln_publication_date", value:"2020/05/18");
      script_set_attribute(attribute:"patch_publication_date", value:"2020/05/20");
      script_set_attribute(attribute:"plugin_publication_date", value:"2020/05/21");
      script_set_attribute(attribute:"generated_plugin", value:"current");
      script_end_attributes();
    
      script_category(ACT_GATHER_INFO);
      script_copyright(english:"This script is Copyright (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof.");
      script_family(english:"Debian Local Security Checks");
    
      script_dependencies("ssh_get_info.nasl");
      script_require_keys("Host/local_checks_enabled", "Host/Debian/release", "Host/Debian/dpkg-l");
    
      exit(0);
    }
    
    
    include("audit.inc");
    include("debian_package.inc");
    
    
    if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
    if (!get_kb_item("Host/Debian/release")) audit(AUDIT_OS_NOT, "Debian");
    if (!get_kb_item("Host/Debian/dpkg-l")) audit(AUDIT_PACKAGE_LIST_MISSING);
    
    
    flag = 0;
    if (deb_check(release:"10.0", prefix:"dovecot-auth-lua", reference:"1:2.3.4.1-5+deb10u2")) flag++;
    if (deb_check(release:"10.0", prefix:"dovecot-core", reference:"1:2.3.4.1-5+deb10u2")) flag++;
    if (deb_check(release:"10.0", prefix:"dovecot-dev", reference:"1:2.3.4.1-5+deb10u2")) flag++;
    if (deb_check(release:"10.0", prefix:"dovecot-gssapi", reference:"1:2.3.4.1-5+deb10u2")) flag++;
    if (deb_check(release:"10.0", prefix:"dovecot-imapd", reference:"1:2.3.4.1-5+deb10u2")) flag++;
    if (deb_check(release:"10.0", prefix:"dovecot-ldap", reference:"1:2.3.4.1-5+deb10u2")) flag++;
    if (deb_check(release:"10.0", prefix:"dovecot-lmtpd", reference:"1:2.3.4.1-5+deb10u2")) flag++;
    if (deb_check(release:"10.0", prefix:"dovecot-lucene", reference:"1:2.3.4.1-5+deb10u2")) flag++;
    if (deb_check(release:"10.0", prefix:"dovecot-managesieved", reference:"1:2.3.4.1-5+deb10u2")) flag++;
    if (deb_check(release:"10.0", prefix:"dovecot-mysql", reference:"1:2.3.4.1-5+deb10u2")) flag++;
    if (deb_check(release:"10.0", prefix:"dovecot-pgsql", reference:"1:2.3.4.1-5+deb10u2")) flag++;
    if (deb_check(release:"10.0", prefix:"dovecot-pop3d", reference:"1:2.3.4.1-5+deb10u2")) flag++;
    if (deb_check(release:"10.0", prefix:"dovecot-sieve", reference:"1:2.3.4.1-5+deb10u2")) flag++;
    if (deb_check(release:"10.0", prefix:"dovecot-solr", reference:"1:2.3.4.1-5+deb10u2")) flag++;
    if (deb_check(release:"10.0", prefix:"dovecot-sqlite", reference:"1:2.3.4.1-5+deb10u2")) flag++;
    if (deb_check(release:"10.0", prefix:"dovecot-submissiond", reference:"1:2.3.4.1-5+deb10u2")) flag++;
    
    if (flag)
    {
      if (report_verbosity > 0) security_warning(port:0, extra:deb_report_get());
      else security_warning(0);
      exit(0);
    }
    else audit(AUDIT_HOST_NOT, "affected");
    

Packetstorm

data sourcehttps://packetstormsecurity.com/files/download/157771/oxdovecot-nullpointerdos.txt
idPACKETSTORM:157771
last seen2020-05-20
published2020-05-19
reporterPhilippe Antoine
sourcehttps://packetstormsecurity.com/files/157771/Open-Xchange-Dovecot-2.3.10-Null-Pointer-Dereference-Denial-Of-Service.html
titleOpen-Xchange Dovecot 2.3.10 Null Pointer Dereference / Denial Of Service

References