Vulnerabilities > CVE-2014-2855 - Improper Input Validation vulnerability in Samba Rsync

047910
CVSS 0.0 - NONE
Attack vector
UNKNOWN
Attack complexity
UNKNOWN
Privileges required
UNKNOWN
Confidentiality impact
UNKNOWN
Integrity impact
UNKNOWN
Availability impact
UNKNOWN

Summary

The check_secret function in authenticate.c in rsync 3.1.0 and earlier allows remote attackers to cause a denial of service (infinite loop and CPU consumption) via a user name which does not exist in the secrets file.

Vulnerable Configurations

Part Description Count
Application
Samba
193

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-2171-1.NASL
    descriptionRyan Finnie discovered that the rsync daemon incorrectly handled invalid usernames. A remote attacker could use this issue to cause rsync to consume resources, resulting in a denial of service. 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 seen2020-06-01
    modified2020-06-02
    plugin id73681
    published2014-04-24
    reporterUbuntu Security Notice (C) 2014-2019 Canonical, Inc. / NASL script (C) 2014-2019 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/73681
    titleUbuntu 14.04 LTS : rsync vulnerability (USN-2171-1)
    code
    #
    # (C) Tenable Network Security, Inc.
    #
    # The descriptive text and package checks in this plugin were
    # extracted from Ubuntu Security Notice USN-2171-1. 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(73681);
      script_version("1.6");
      script_cvs_date("Date: 2019/09/19 12:54:30");
    
      script_cve_id("CVE-2014-2855");
      script_bugtraq_id(66929);
      script_xref(name:"USN", value:"2171-1");
    
      script_name(english:"Ubuntu 14.04 LTS : rsync vulnerability (USN-2171-1)");
      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:
    "Ryan Finnie discovered that the rsync daemon incorrectly handled
    invalid usernames. A remote attacker could use this issue to cause
    rsync to consume resources, resulting in a denial of service.
    
    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/2171-1/"
      );
      script_set_attribute(attribute:"solution", value:"Update the affected rsync package.");
      script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:C");
      script_set_cvss_temporal_vector("CVSS2#E:ND/RL:OF/RC:C");
      script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
      script_set_attribute(attribute:"exploit_available", value:"false");
    
      script_set_attribute(attribute:"plugin_type", value:"local");
      script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:rsync");
      script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:14.04");
    
      script_set_attribute(attribute:"vuln_publication_date", value:"2014/04/23");
      script_set_attribute(attribute:"patch_publication_date", value:"2014/04/23");
      script_set_attribute(attribute:"plugin_publication_date", value:"2014/04/24");
      script_set_attribute(attribute:"generated_plugin", value:"current");
      script_end_attributes();
    
      script_category(ACT_GATHER_INFO);
      script_copyright(english:"Ubuntu Security Notice (C) 2014-2019 Canonical, Inc. / NASL script (C) 2014-2019 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:"^(14\.04)$", string:release)) audit(AUDIT_OS_NOT, "Ubuntu 14.04", "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:"14.04", pkgname:"rsync", pkgver:"3.1.0-2ubuntu0.1")) flag++;
    
    if (flag)
    {
      security_report_v4(
        port       : 0,
        severity   : SECURITY_HOLE,
        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, "rsync");
    }
    
  • NASL familySuSE Local Security Checks
    NASL idOPENSUSE-2014-332.NASL
    descriptionRsync was updated to fix a denial of service attack that could be used by remote attackers without authentification (CVE-2014-2855).
    last seen2020-06-05
    modified2014-06-13
    plugin id75342
    published2014-06-13
    reporterThis script is Copyright (C) 2014-2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/75342
    titleopenSUSE Security Update : Rsync (openSUSE-SU-2014:0595-1)
    code
    #%NASL_MIN_LEVEL 80502
    #
    # (C) Tenable Network Security, Inc.
    #
    # The descriptive text and package checks in this plugin were
    # extracted from openSUSE Security Update openSUSE-2014-332.
    #
    # The text description of this plugin is (C) SUSE LLC.
    #
    
    include("compat.inc");
    
    if (description)
    {
      script_id(75342);
      script_version("1.4");
      script_set_attribute(attribute:"plugin_modification_date", value:"2020/06/04");
    
      script_cve_id("CVE-2014-2855");
    
      script_name(english:"openSUSE Security Update : Rsync (openSUSE-SU-2014:0595-1)");
      script_summary(english:"Check for the openSUSE-2014-332 patch");
    
      script_set_attribute(
        attribute:"synopsis", 
        value:"The remote openSUSE host is missing a security update."
      );
      script_set_attribute(
        attribute:"description", 
        value:
    "Rsync was updated to fix a denial of service attack that could be used
    by remote attackers without authentification (CVE-2014-2855)."
      );
      script_set_attribute(
        attribute:"see_also",
        value:"https://bugzilla.novell.com/show_bug.cgi?id=873740"
      );
      script_set_attribute(
        attribute:"see_also",
        value:"https://lists.opensuse.org/opensuse-updates/2014-05/msg00006.html"
      );
      script_set_attribute(
        attribute:"solution", 
        value:"Update the affected Rsync packages."
      );
      script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:C");
    
      script_set_attribute(attribute:"plugin_type", value:"local");
      script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:rsync");
      script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:rsync-debuginfo");
      script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:rsync-debugsource");
      script_set_attribute(attribute:"cpe", value:"cpe:/o:novell:opensuse:13.1");
    
      script_set_attribute(attribute:"patch_publication_date", value:"2014/04/22");
      script_set_attribute(attribute:"plugin_publication_date", value:"2014/06/13");
      script_end_attributes();
    
      script_category(ACT_GATHER_INFO);
      script_copyright(english:"This script is Copyright (C) 2014-2020 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 !~ "^(SUSE13\.1)$") audit(AUDIT_OS_RELEASE_NOT, "openSUSE", "13.1", 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 !~ "^(i586|i686|x86_64)$") audit(AUDIT_ARCH_NOT, "i586 / i686 / x86_64", ourarch);
    
    flag = 0;
    
    if ( rpm_check(release:"SUSE13.1", reference:"rsync-3.1.0-21.8.1") ) flag++;
    if ( rpm_check(release:"SUSE13.1", reference:"rsync-debuginfo-3.1.0-21.8.1") ) flag++;
    if ( rpm_check(release:"SUSE13.1", reference:"rsync-debugsource-3.1.0-21.8.1") ) flag++;
    
    if (flag)
    {
      if (report_verbosity > 0) security_hole(port:0, extra:rpm_report_get());
      else security_hole(0);
      exit(0);
    }
    else
    {
      tested = pkg_tests_get();
      if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
      else audit(AUDIT_PACKAGE_NOT_INSTALLED, "Rsync");
    }
    
  • NASL familyMandriva Local Security Checks
    NASL idMANDRIVA_MDVSA-2015-131.NASL
    descriptionUpdated rsync package fixes security vulnerability : Ryan Finnie discovered that rsync 3.1.0 contains a denial of service issue when attempting to authenticate using a nonexistent username. A remote attacker could use this flaw to cause a denial of service via CPU consumption (CVE-2014-2855).
    last seen2020-06-01
    modified2020-06-02
    plugin id82384
    published2015-03-30
    reporterThis script is Copyright (C) 2015-2019 Tenable Network Security, Inc.
    sourcehttps://www.tenable.com/plugins/nessus/82384
    titleMandriva Linux Security Advisory : rsync (MDVSA-2015:131)
  • NASL familyFedora Local Security Checks
    NASL idFEDORA_2014-5315.NASL
    descriptionThis update fixes CVE-2014-2855 and temporary reverts compilation with system provided zlib(BZ#1043965). Note that Tenable Network Security has extracted the preceding description block directly from the Fedora security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.
    last seen2020-03-17
    modified2014-04-21
    plugin id73631
    published2014-04-21
    reporterThis script is Copyright (C) 2014-2020 Tenable Network Security, Inc.
    sourcehttps://www.tenable.com/plugins/nessus/73631
    titleFedora 20 : rsync-3.1.0-3.fc20 (2014-5315)

Seebug

bulletinFamilyexploit
descriptionCVE ID:CVE-2014-2855 rsync是一款文件同步管理软件。 rsync处理不存在用户时存在安全漏洞,可消耗大量CPU资源,造成拒绝服务攻击。 0 rsync 3.1.0 目前厂商已经发布了升级补丁以修复漏洞,请下载使用: https://git.samba.org/?p=rsync.git;a=commitdiff;h=0dedfbce2c1b851684ba658861fe9d620636c56a
idSSV:62221
last seen2017-11-19
modified2014-04-18
published2014-04-18
reporterRoot
titlersync不存在用户处理CPU消耗拒绝服务漏洞