Vulnerabilities > CVE-2008-2936 - Permissions, Privileges, and Access Controls vulnerability in Postfix

#%NASL_MIN_LEVEL 80502
#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were  
# extracted from Debian Security Advisory DSA-1629. The text 
# itself is copyright (C) Software in the Public Interest, Inc.
#

include("compat.inc");

if (description)
{
  script_id(33934);
  script_version("1.16");
  script_cvs_date("Date: 2019/08/02 13:32:21");

  script_cve_id("CVE-2008-2936");
  script_bugtraq_id(30691);
  script_xref(name:"DSA", value:"1629");

  script_name(english:"Debian DSA-1629-2 : postfix - programming error");
  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:
"Sebastian Krahmer discovered that Postfix, a mail transfer agent,
incorrectly checks the ownership of a mailbox. In some configurations,
this allows for appending data to arbitrary files as root.

Note that only specific configurations are vulnerable; the default
Debian installation is not affected. Only a configuration meeting the
following requirements is vulnerable :

  - The mail delivery style is mailbox, with the Postfix
    built-in local(8) or virtual(8) delivery agents.
  - The mail spool directory (/var/spool/mail) is
    user-writeable.

  - The user can create hardlinks pointing to root-owned
    symlinks located in other directories.

For a detailed treating of the issue, please refer to the upstream
author's announcement."
  );
  script_set_attribute(
    attribute:"see_also",
    value:"http://article.gmane.org/gmane.mail.postfix.announce/110"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://www.debian.org/security/2008/dsa-1629"
  );
  script_set_attribute(
    attribute:"solution", 
    value:
"Upgrade the postfix package.

For the stable distribution (etch), this problem has been fixed in
version 2.3.8-2+etch1."
  );
  script_set_cvss_base_vector("CVSS2#AV:L/AC:H/Au:N/C:C/I:C/A:C");
  script_set_cvss_temporal_vector("CVSS2#E:POC/RL:OF/RC:C");
  script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"true");
  script_set_attribute(attribute:"exploited_by_malware", value:"true");
  script_cwe_id(264);

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:postfix");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:4.0");

  script_set_attribute(attribute:"vuln_publication_date", value:"2008/08/18");
  script_set_attribute(attribute:"patch_publication_date", value:"2008/08/19");
  script_set_attribute(attribute:"plugin_publication_date", value:"2008/08/19");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"This script is Copyright (C) 2008-2019 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:"4.0", prefix:"postfix", reference:"2.3.8-2+etch1")) flag++;
if (deb_check(release:"4.0", prefix:"postfix-cdb", reference:"2.3.8-2+etch1")) flag++;
if (deb_check(release:"4.0", prefix:"postfix-dev", reference:"2.3.8-2+etch1")) flag++;
if (deb_check(release:"4.0", prefix:"postfix-doc", reference:"2.3.8-2+etch1")) flag++;
if (deb_check(release:"4.0", prefix:"postfix-ldap", reference:"2.3.8-2+etch1")) flag++;
if (deb_check(release:"4.0", prefix:"postfix-mysql", reference:"2.3.8-2+etch1")) flag++;
if (deb_check(release:"4.0", prefix:"postfix-pcre", reference:"2.3.8-2+etch1")) flag++;
if (deb_check(release:"4.0", prefix:"postfix-pgsql", reference:"2.3.8-2+etch1")) 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");

#%NASL_MIN_LEVEL 80502
#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were  
# extracted from Fedora Security Advisory 2008-8593.
#

include("compat.inc");

if (description)
{
  script_id(34376);
  script_version ("1.19");
  script_cvs_date("Date: 2019/08/02 13:32:28");

  script_cve_id("CVE-2008-2936", "CVE-2008-2937", "CVE-2008-3889");
  script_bugtraq_id(30691, 30977);
  script_xref(name:"FEDORA", value:"2008-8593");

  script_name(english:"Fedora 9 : postfix-2.5.5-1.fc9 (2008-8593)");
  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:
"New upstream patch level version 2.5.5, including multiple security
fixes detailed in upstream announcements:
http://www.postfix.org/announcements/20080814.html
http://www.postfix.org/announcements/20080902.html

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."
  );
  script_set_attribute(
    attribute:"see_also",
    value:"http://www.postfix.org/announcements/20080814.html"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"http://www.postfix.org/announcements/20080902.html"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://bugzilla.redhat.com/show_bug.cgi?id=456314"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://bugzilla.redhat.com/show_bug.cgi?id=456347"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://bugzilla.redhat.com/show_bug.cgi?id=460906"
  );
  # https://lists.fedoraproject.org/pipermail/package-announce/2008-October/015227.html
  script_set_attribute(
    attribute:"see_also",
    value:"http://www.nessus.org/u?c386e55d"
  );
  script_set_attribute(
    attribute:"solution", 
    value:"Update the affected postfix package."
  );
  script_set_cvss_base_vector("CVSS2#AV:L/AC:H/Au:N/C:C/I:C/A:C");
  script_set_cvss_temporal_vector("CVSS2#E:POC/RL:OF/RC:C");
  script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"true");
  script_set_attribute(attribute:"exploited_by_malware", value:"true");
  script_cwe_id(20, 200, 264);

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:fedoraproject:fedora:postfix");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:fedoraproject:fedora:9");

  script_set_attribute(attribute:"vuln_publication_date", value:"2008/08/18");
  script_set_attribute(attribute:"patch_publication_date", value:"2008/10/09");
  script_set_attribute(attribute:"plugin_publication_date", value:"2008/10/10");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"This script is Copyright (C) 2008-2019 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 = eregmatch(pattern: "Fedora.*release ([0-9]+)", string:release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, "Fedora");
os_ver = os_ver[1];
if (! ereg(pattern:"^9([^0-9]|$)", string:os_ver)) audit(AUDIT_OS_NOT, "Fedora 9.x", "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:"FC9", reference:"postfix-2.5.5-1.fc9")) 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, "postfix");
}

#%NASL_MIN_LEVEL 80502
#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Gentoo Linux Security Advisory GLSA 200808-12.
#
# The advisory text is Copyright (C) 2001-2019 Gentoo Foundation, Inc.
# and licensed under the Creative Commons - Attribution / Share Alike 
# license. See http://creativecommons.org/licenses/by-sa/3.0/
#

include("compat.inc");

if (description)
{
  script_id(33891);
  script_version("1.17");
  script_cvs_date("Date: 2019/08/02 13:32:45");

  script_cve_id("CVE-2008-2936", "CVE-2008-2937");
  script_xref(name:"GLSA", value:"200808-12");

  script_name(english:"GLSA-200808-12 : Postfix: Local privilege escalation vulnerability");
  script_summary(english:"Checks for updated package(s) in /var/db/pkg");

  script_set_attribute(
    attribute:"synopsis", 
    value:
"The remote Gentoo host is missing one or more security-related
patches."
  );
  script_set_attribute(
    attribute:"description", 
    value:
"The remote host is affected by the vulnerability described in GLSA-200808-12
(Postfix: Local privilege escalation vulnerability)

    Sebastian Krahmer of SuSE has found that Postfix allows to deliver mail
    to root-owned symlinks in an insecure manner under certain conditions.
    Normally, Postfix does not deliver mail to symlinks, except to
    root-owned symlinks, for compatibility with the systems using symlinks
    in /dev like Solaris. Furthermore, some systems like Linux allow to
    hardlink a symlink, while the POSIX.1-2001 standard requires that the
    symlink is followed. Depending on the write permissions and the
    delivery agent being used, this can lead to an arbitrary local file
    overwriting vulnerability (CVE-2008-2936). Furthermore, the Postfix
    delivery agent does not properly verify the ownership of a mailbox
    before delivering mail (CVE-2008-2937).
  
Impact :

    The combination of these features allows a local attacker to hardlink a
    root-owned symlink such that the newly created symlink would be
    root-owned and would point to a regular file (or another symlink) that
    would be written by the Postfix built-in local(8) or virtual(8)
    delivery agents, regardless the ownership of the final destination
    regular file. Depending on the write permissions of the spool mail
    directory, the delivery style, and the existence of a root mailbox,
    this could allow a local attacker to append a mail to an arbitrary file
    like /etc/passwd in order to gain root privileges.
    The default configuration of Gentoo Linux does not permit any kind of
    user privilege escalation.
    The second vulnerability (CVE-2008-2937) allows a local attacker,
    already having write permissions to the mail spool directory which is
    not the case on Gentoo by default, to create a previously nonexistent
    mailbox before Postfix creates it, allowing to read the mail of another
    user on the system.
  
Workaround :

    The following conditions should be met in order to be vulnerable to
    local privilege escalation.
    The mail delivery style is mailbox, with the Postfix built-in
    local(8) or virtual(8) delivery agents.
    The mail spool directory (/var/spool/mail) is user-writeable.
    The user can create hardlinks pointing to root-owned symlinks
    located in other directories.
    Consequently, each one of the following workarounds is efficient.
    Verify that your /var/spool/mail directory is not writeable by a
    user. Normally on Gentoo, only the mail group has write access, and no
    end-user should be granted the mail group ownership.
    Prevent the local users from being able to create hardlinks
    pointing outside of the /var/spool/mail directory, e.g. with a
    dedicated partition.
    Use a non-builtin Postfix delivery agent, like procmail or
    maildrop.
    Use the maildir delivery style of Postfix ('home_mailbox=Maildir/'
    for example).
    Concerning the second vulnerability, check the write permissions of
    /var/spool/mail, or check that every Unix account already has a
    mailbox, by using Wietse Venema's Perl script available in the official
    advisory."
  );
  script_set_attribute(
    attribute:"see_also",
    value:"http://article.gmane.org/gmane.mail.postfix.announce/110"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://security.gentoo.org/glsa/200808-12"
  );
  script_set_attribute(
    attribute:"solution", 
    value:
"All Postfix users should upgrade to the latest version:
    # emerge --sync
    # emerge --ask --oneshot --verbose '>=mail-mta/postfix-2.5.3-r1'"
  );
  script_set_cvss_base_vector("CVSS2#AV:L/AC:H/Au:N/C:C/I:C/A:C");
  script_set_cvss_temporal_vector("CVSS2#E:POC/RL:OF/RC:C");
  script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"true");
  script_set_attribute(attribute:"exploited_by_malware", value:"true");
  script_cwe_id(200, 264);

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:gentoo:linux:postfix");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:gentoo:linux");

  script_set_attribute(attribute:"vuln_publication_date", value:"2008/08/18");
  script_set_attribute(attribute:"patch_publication_date", value:"2008/08/14");
  script_set_attribute(attribute:"plugin_publication_date", value:"2008/08/15");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"This script is Copyright (C) 2008-2019 and is owned by Tenable, Inc. or an Affiliate thereof.");
  script_family(english:"Gentoo Local Security Checks");

  script_dependencies("ssh_get_info.nasl");
  script_require_keys("Host/local_checks_enabled", "Host/Gentoo/release", "Host/Gentoo/qpkg-list");

  exit(0);
}


include("audit.inc");
include("global_settings.inc");
include("qpkg.inc");

if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
if (!get_kb_item("Host/Gentoo/release")) audit(AUDIT_OS_NOT, "Gentoo");
if (!get_kb_item("Host/Gentoo/qpkg-list")) audit(AUDIT_PACKAGE_LIST_MISSING);


flag = 0;

if (qpkg_check(package:"mail-mta/postfix", unaffected:make_list("rge 2.4.7-r1", "ge 2.5.3-r1", "rge 2.4.8", "ge 2.4.9"), vulnerable:make_list("lt 2.5.3-r1"))) flag++;

if (flag)
{
  if (report_verbosity > 0) security_warning(port:0, extra:qpkg_report_get());
  else security_warning(0);
  exit(0);
}
else
{
  tested = qpkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, "Postfix");
}

#%NASL_MIN_LEVEL 80502
#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were  
# extracted from Red Hat Security Advisory RHSA-2008:0839 and 
# CentOS Errata and Security Advisory 2008:0839 respectively.
#

include("compat.inc");

if (description)
{
  script_id(33890);
  script_version("1.16");
  script_cvs_date("Date: 2019/10/25 13:36:04");

  script_cve_id("CVE-2008-2936");
  script_bugtraq_id(30691);
  script_xref(name:"RHSA", value:"2008:0839");

  script_name(english:"CentOS 3 / 4 / 5 : postfix (CESA-2008:0839)");
  script_summary(english:"Checks rpm output for the updated packages");

  script_set_attribute(
    attribute:"synopsis", 
    value:"The remote CentOS host is missing one or more security updates."
  );
  script_set_attribute(
    attribute:"description", 
    value:
"Updated postfix packages that fix a security issue are now available
for Red Hat Enterprise Linux 3, 4, and 5.

This update has been rated as having moderate security impact by the
Red Hat Security Response Team.

Postfix is a Mail Transport Agent (MTA), supporting LDAP, SMTP AUTH
(SASL), and TLS.

A flaw was found in the way Postfix dereferences symbolic links. If a
local user has write access to a mail spool directory with no root
mailbox, it may be possible for them to append arbitrary data to files
that root has write permission to. (CVE-2008-2936)

Red Hat would like to thank Sebastian Krahmer for responsibly
disclosing this issue.

All users of postfix should upgrade to these updated packages, which
contain a backported patch that resolves this issue."
  );
  # https://lists.centos.org/pipermail/centos-announce/2008-August/015185.html
  script_set_attribute(
    attribute:"see_also",
    value:"http://www.nessus.org/u?0e846042"
  );
  # https://lists.centos.org/pipermail/centos-announce/2008-August/015186.html
  script_set_attribute(
    attribute:"see_also",
    value:"http://www.nessus.org/u?0f99e39b"
  );
  # https://lists.centos.org/pipermail/centos-announce/2008-August/015187.html
  script_set_attribute(
    attribute:"see_also",
    value:"http://www.nessus.org/u?040893ac"
  );
  # https://lists.centos.org/pipermail/centos-announce/2008-August/015188.html
  script_set_attribute(
    attribute:"see_also",
    value:"http://www.nessus.org/u?049939bc"
  );
  # https://lists.centos.org/pipermail/centos-announce/2008-August/015197.html
  script_set_attribute(
    attribute:"see_also",
    value:"http://www.nessus.org/u?794c4583"
  );
  # https://lists.centos.org/pipermail/centos-announce/2008-August/015199.html
  script_set_attribute(
    attribute:"see_also",
    value:"http://www.nessus.org/u?b71a314a"
  );
  script_set_attribute(
    attribute:"solution", 
    value:"Update the affected postfix packages."
  );
  script_set_cvss_base_vector("CVSS2#AV:L/AC:H/Au:N/C:C/I:C/A:C");
  script_set_cvss_temporal_vector("CVSS2#E:POC/RL:OF/RC:C");
  script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"true");
  script_set_attribute(attribute:"exploited_by_malware", value:"true");
  script_cwe_id(264);

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:postfix");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:postfix-pflogsumm");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:centos:centos:3");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:centos:centos:4");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:centos:centos:5");

  script_set_attribute(attribute:"vuln_publication_date", value:"2008/08/18");
  script_set_attribute(attribute:"patch_publication_date", value:"2008/08/23");
  script_set_attribute(attribute:"plugin_publication_date", value:"2008/08/15");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"This script is Copyright (C) 2008-2019 and is owned by Tenable, Inc. or an Affiliate thereof.");
  script_family(english:"CentOS Local Security Checks");

  script_dependencies("ssh_get_info.nasl");
  script_require_keys("Host/local_checks_enabled", "Host/CentOS/release", "Host/CentOS/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/CentOS/release");
if (isnull(release) || "CentOS" >!< release) audit(AUDIT_OS_NOT, "CentOS");
os_ver = pregmatch(pattern: "CentOS(?: Linux)? release ([0-9]+)", string:release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, "CentOS");
os_ver = os_ver[1];
if (! preg(pattern:"^(3|4|5)([^0-9]|$)", string:os_ver)) audit(AUDIT_OS_NOT, "CentOS 3.x / 4.x / 5.x", "CentOS " + os_ver);

if (!get_kb_item("Host/CentOS/rpm-list")) audit(AUDIT_PACKAGE_LIST_MISSING);


cpu = get_kb_item("Host/cpu");
if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH);
if ("x86_64" >!< cpu && "ia64" >!< cpu && cpu !~ "^i[3-6]86$") audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, "CentOS", cpu);


flag = 0;
if (rpm_check(release:"CentOS-3", reference:"postfix-2.0.16-14.1.RHEL3")) flag++;

if (rpm_check(release:"CentOS-4", cpu:"ia64", reference:"postfix-2.2.10-1.2.1.c4")) flag++;
if (rpm_check(release:"CentOS-4", cpu:"ia64", reference:"postfix-pflogsumm-2.2.10-1.2.1.c4")) flag++;

if (rpm_check(release:"CentOS-5", reference:"postfix-2.3.3-2.1.el5_2")) flag++;
if (rpm_check(release:"CentOS-5", reference:"postfix-pflogsumm-2.3.3-2.1.el5_2")) 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, "postfix / postfix-pflogsumm");
}