Vulnerabilities > CVE-2016-9963 - Key Management Errors vulnerability in multiple products

047910
CVSS 2.6 - LOW
Attack vector
NETWORK
Attack complexity
HIGH
Privileges required
NONE
Confidentiality impact
PARTIAL
Integrity impact
NONE
Availability impact
NONE
network
high complexity
exim
canonical
debian
CWE-320
nessus

Summary

Exim before 4.87.1 might allow remote attackers to obtain the private DKIM signing key via vectors related to log files and bounce messages.

Vulnerable Configurations

Part Description Count
Application
Exim
96
OS
Canonical
4
OS
Debian
1

Common Weakness Enumeration (CWE)

Nessus

  • NASL familyAmazon Linux Local Security Checks
    NASL idALA_ALAS-2017-804.NASL
    descriptionIt was found that Exim leaked DKIM signing private keys to the
    last seen2020-06-01
    modified2020-06-02
    plugin id97556
    published2017-03-07
    reporterThis script is Copyright (C) 2017-2018 Tenable Network Security, Inc.
    sourcehttps://www.tenable.com/plugins/nessus/97556
    titleAmazon Linux AMI : exim (ALAS-2017-804)
    code
    #
    # (C) Tenable Network Security, Inc.
    #
    # The descriptive text and package checks in this plugin were
    # extracted from Amazon Linux AMI Security Advisory ALAS-2017-804.
    #
    
    include("compat.inc");
    
    if (description)
    {
      script_id(97556);
      script_version("3.2");
      script_cvs_date("Date: 2018/04/18 15:09:36");
    
      script_cve_id("CVE-2016-9963");
      script_xref(name:"ALAS", value:"2017-804");
    
      script_name(english:"Amazon Linux AMI : exim (ALAS-2017-804)");
      script_summary(english:"Checks rpm output for the updated packages");
    
      script_set_attribute(
        attribute:"synopsis", 
        value:"The remote Amazon Linux AMI host is missing a security update."
      );
      script_set_attribute(
        attribute:"description", 
        value:
    "It was found that Exim leaked DKIM signing private keys to the
    'mainlog' log file. As a result, an attacker with access to system log
    files could potentially access these leaked DKIM private keys."
      );
      script_set_attribute(
        attribute:"see_also",
        value:"https://alas.aws.amazon.com/ALAS-2017-804.html"
      );
      script_set_attribute(
        attribute:"solution", 
        value:"Run 'yum update exim' to update your system."
      );
      script_set_cvss_base_vector("CVSS2#AV:N/AC:H/Au:N/C:P/I:N/A:N");
      script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N");
    
      script_set_attribute(attribute:"plugin_type", value:"local");
      script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:exim");
      script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:exim-debuginfo");
      script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:exim-greylist");
      script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:exim-mon");
      script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:exim-mysql");
      script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:exim-pgsql");
      script_set_attribute(attribute:"cpe", value:"cpe:/o:amazon:linux");
    
      script_set_attribute(attribute:"patch_publication_date", value:"2017/03/06");
      script_set_attribute(attribute:"plugin_publication_date", value:"2017/03/07");
      script_end_attributes();
    
      script_category(ACT_GATHER_INFO);
      script_copyright(english:"This script is Copyright (C) 2017-2018 Tenable Network Security, Inc.");
      script_family(english:"Amazon Linux Local Security Checks");
    
      script_dependencies("ssh_get_info.nasl");
      script_require_keys("Host/local_checks_enabled", "Host/AmazonLinux/release", "Host/AmazonLinux/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/AmazonLinux/release");
    if (isnull(release) || !strlen(release)) audit(AUDIT_OS_NOT, "Amazon Linux");
    os_ver = pregmatch(pattern: "^AL(A|\d)", string:release);
    if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, "Amazon Linux");
    os_ver = os_ver[1];
    if (os_ver != "A")
    {
      if (os_ver == 'A') os_ver = 'AMI';
      audit(AUDIT_OS_NOT, "Amazon Linux AMI", "Amazon Linux " + os_ver);
    }
    
    if (!get_kb_item("Host/AmazonLinux/rpm-list")) audit(AUDIT_PACKAGE_LIST_MISSING);
    
    
    flag = 0;
    if (rpm_check(release:"ALA", reference:"exim-4.88-2.11.amzn1")) flag++;
    if (rpm_check(release:"ALA", reference:"exim-debuginfo-4.88-2.11.amzn1")) flag++;
    if (rpm_check(release:"ALA", reference:"exim-greylist-4.88-2.11.amzn1")) flag++;
    if (rpm_check(release:"ALA", reference:"exim-mon-4.88-2.11.amzn1")) flag++;
    if (rpm_check(release:"ALA", reference:"exim-mysql-4.88-2.11.amzn1")) flag++;
    if (rpm_check(release:"ALA", reference:"exim-pgsql-4.88-2.11.amzn1")) flag++;
    
    if (flag)
    {
      if (report_verbosity > 0) security_note(port:0, extra:rpm_report_get());
      else security_note(0);
      exit(0);
    }
    else
    {
      tested = pkg_tests_get();
      if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
      else audit(AUDIT_PACKAGE_NOT_INSTALLED, "exim / exim-debuginfo / exim-greylist / exim-mon / exim-mysql / etc");
    }
    
  • NASL familyFreeBSD Local Security Checks
    NASL idFREEBSD_PKG_E7002B26CAAA11E6A76A9F7324E5534E.NASL
    descriptionThe Exim project reports : Exim leaks the private DKIM signing key to the log files. Additionally, if the build option EXPERIMENTAL_DSN_INFO=yes is used, the key material is included in the bounce message.
    last seen2020-06-01
    modified2020-06-02
    plugin id96122
    published2016-12-27
    reporterThis script is Copyright (C) 2016-2018 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/96122
    titleFreeBSD : exim -- DKIM private key leak (e7002b26-caaa-11e6-a76a-9f7324e5534e)
    code
    #
    # (C) Tenable Network Security, Inc.
    #
    # The descriptive text and package checks in this plugin were  
    # extracted from the FreeBSD VuXML database :
    #
    # Copyright 2003-2018 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(96122);
      script_version("3.5");
      script_cvs_date("Date: 2018/11/10 11:49:46");
    
      script_cve_id("CVE-2016-9963");
    
      script_name(english:"FreeBSD : exim -- DKIM private key leak (e7002b26-caaa-11e6-a76a-9f7324e5534e)");
      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:
    "The Exim project reports :
    
    Exim leaks the private DKIM signing key to the log files.
    Additionally, if the build option EXPERIMENTAL_DSN_INFO=yes is used,
    the key material is included in the bounce message."
      );
      script_set_attribute(
        attribute:"see_also",
        value:"https://exim.org/static/doc/CVE-2016-9963.txt"
      );
      # https://vuxml.freebsd.org/freebsd/e7002b26-caaa-11e6-a76a-9f7324e5534e.html
      script_set_attribute(
        attribute:"see_also",
        value:"http://www.nessus.org/u?02b7365f"
      );
      script_set_attribute(attribute:"solution", value:"Update the affected package.");
      script_set_cvss_base_vector("CVSS2#AV:N/AC:H/Au:N/C:P/I:N/A:N");
      script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N");
    
      script_set_attribute(attribute:"plugin_type", value:"local");
      script_set_attribute(attribute:"cpe", value:"p-cpe:/a:freebsd:freebsd:exim");
      script_set_attribute(attribute:"cpe", value:"cpe:/o:freebsd:freebsd");
    
      script_set_attribute(attribute:"vuln_publication_date", value:"2016/12/15");
      script_set_attribute(attribute:"patch_publication_date", value:"2016/12/25");
      script_set_attribute(attribute:"plugin_publication_date", value:"2016/12/27");
      script_end_attributes();
    
      script_category(ACT_GATHER_INFO);
      script_copyright(english:"This script is Copyright (C) 2016-2018 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:"exim>4.69<4.87.1")) flag++;
    
    if (flag)
    {
      if (report_verbosity > 0) security_note(port:0, extra:pkg_report_get());
      else security_note(0);
      exit(0);
    }
    else audit(AUDIT_HOST_NOT, "affected");
    
  • NASL familySuSE Local Security Checks
    NASL idOPENSUSE-2017-980.NASL
    descriptionThis update for exim fixes the following issues : Changes in exim : - specify users with ref:mail, to make them dynamic. (boo#1046971) - CVE-2017-1000369: Fixed memory leaks that could be exploited to
    last seen2020-06-05
    modified2017-08-30
    plugin id102834
    published2017-08-30
    reporterThis script is Copyright (C) 2017-2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/102834
    titleopenSUSE Security Update : exim (openSUSE-2017-980) (Stack Clash)
  • NASL familyUbuntu Local Security Checks
    NASL idUBUNTU_USN-3164-1.NASL
    descriptionBjoern Jacke discovered that Exim incorrectly handled DKIM keys. In certain configurations, private DKIM signing keys could be leaked to the log files. 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 id96336
    published2017-01-06
    reporterUbuntu Security Notice (C) 2017-2019 Canonical, Inc. / NASL script (C) 2017-2019 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/96336
    titleUbuntu 12.04 LTS / 14.04 LTS / 16.04 LTS / 16.10 : exim4 vulnerability (USN-3164-1)
  • NASL familyDebian Local Security Checks
    NASL idDEBIAN_DLA-762.NASL
    descriptionBjoern Jacke discovered that Exim, Debian
    last seen2020-03-17
    modified2016-12-27
    plugin id96097
    published2016-12-27
    reporterThis script is Copyright (C) 2016-2020 Tenable Network Security, Inc.
    sourcehttps://www.tenable.com/plugins/nessus/96097
    titleDebian DLA-762-1 : exim4 security update
  • NASL familyDebian Local Security Checks
    NASL idDEBIAN_DSA-3747.NASL
    descriptionBjoern Jacke discovered that Exim, Debian
    last seen2020-06-01
    modified2020-06-02
    plugin id96104
    published2016-12-27
    reporterThis script is Copyright (C) 2016-2018 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/96104
    titleDebian DSA-3747-1 : exim4 - security update