SUSE SLED11 / SLES11 Security Update : openssh (SUSE-SU-2015:1695-1) (Logjam)

2015-10-12T00:00:00
ID SUSE_SU-2015-1695-1.NASL
Type nessus
Reporter This script is Copyright (C) 2015-2019 and is owned by Tenable, Inc. or an Affiliate thereof.
Modified 2020-05-02T00:00:00

Description

OpenSSH was updated to fix several security issues and bugs.

Please note that due to a bug in the previous shipped openssh version, sshd might not correctly restart. Please verify that the ssh daemon is running after installing this update.

These security issues were fixed :

  • CVE-2015-5352: The x11_open_helper function, when ForwardX11Trusted mode is not used, lacked a check of the refusal deadline for X connections, which made it easier for remote attackers to bypass intended access restrictions via a connection outside of the permitted time window. (bsc#936695)

  • CVE-2015-5600: The kbdint_next_device function in auth2-chall.c in sshd did not properly restrict the processing of keyboard-interactive devices within a single connection, which made it easier for remote attackers to conduct brute-force attacks or cause a denial of service (CPU consumption) via a long and duplicative list in the ssh

    -oKbdInteractiveDevices option, as demonstrated by a modified client that provides a different password for each pam element on this list. (bsc#938746)

  • CVE-2015-4000: Removed and disabled weak DH groups to address LOGJAM. (bsc#932483)

  • Hardening patch to fix sftp RCE. (bsc#903649)

  • CVE-2015-6563: The monitor component in sshd accepted extraneous username data in MONITOR_REQ_PAM_INIT_CTX requests, which allowed local users to conduct impersonation attacks by leveraging any SSH login access in conjunction with control of the sshd uid to send a crafted MONITOR_REQ_PWNAM request, related to monitor.c and monitor_wrap.c.

  • CVE-2015-6564: Use-after-free vulnerability in the mm_answer_pam_free_ctx function in monitor.c in sshd might have allowed local users to gain privileges by leveraging control of the sshd uid to send an unexpectedly early MONITOR_REQ_PAM_FREE_CTX request.

Additional a bug was fixed that could lead to openssh not working in chroot (bsc#947458).

Note that Tenable Network Security has extracted the preceding description block directly from the SUSE security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

                                        
                                            #
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from SUSE update advisory SUSE-SU-2015:1695-1.
# The text itself is copyright (C) SUSE.
#

include("compat.inc");

if (description)
{
  script_id(86339);
  script_version("2.8");
  script_cvs_date("Date: 2019/09/11 11:22:12");

  script_cve_id("CVE-2015-4000", "CVE-2015-5352", "CVE-2015-5600", "CVE-2015-6563", "CVE-2015-6564");
  script_bugtraq_id(74733, 75525);

  script_name(english:"SUSE SLED11 / SLES11 Security Update : openssh (SUSE-SU-2015:1695-1) (Logjam)");
  script_summary(english:"Checks rpm output for the updated packages.");

  script_set_attribute(
    attribute:"synopsis", 
    value:"The remote SUSE host is missing one or more security updates."
  );
  script_set_attribute(
    attribute:"description", 
    value:
"OpenSSH was updated to fix several security issues and bugs.

Please note that due to a bug in the previous shipped openssh version,
sshd might not correctly restart. Please verify that the ssh daemon is
running after installing this update.

These security issues were fixed :

  - CVE-2015-5352: The x11_open_helper function, when
    ForwardX11Trusted mode is not used, lacked a check of
    the refusal deadline for X connections, which made it
    easier for remote attackers to bypass intended access
    restrictions via a connection outside of the permitted
    time window. (bsc#936695)

  - CVE-2015-5600: The kbdint_next_device function in
    auth2-chall.c in sshd did not properly restrict the
    processing of keyboard-interactive devices within a
    single connection, which made it easier for remote
    attackers to conduct brute-force attacks or cause a
    denial of service (CPU consumption) via a long and
    duplicative list in the ssh

    -oKbdInteractiveDevices option, as demonstrated by a
    modified client that provides a different password for
    each pam element on this list. (bsc#938746)

  - CVE-2015-4000: Removed and disabled weak DH groups to
    address LOGJAM. (bsc#932483)

  - Hardening patch to fix sftp RCE. (bsc#903649)

  - CVE-2015-6563: The monitor component in sshd accepted
    extraneous username data in MONITOR_REQ_PAM_INIT_CTX
    requests, which allowed local users to conduct
    impersonation attacks by leveraging any SSH login access
    in conjunction with control of the sshd uid to send a
    crafted MONITOR_REQ_PWNAM request, related to monitor.c
    and monitor_wrap.c.

  - CVE-2015-6564: Use-after-free vulnerability in the
    mm_answer_pam_free_ctx function in monitor.c in sshd
    might have allowed local users to gain privileges by
    leveraging control of the sshd uid to send an
    unexpectedly early MONITOR_REQ_PAM_FREE_CTX request.

Additional a bug was fixed that could lead to openssh not working in
chroot (bsc#947458).

Note that Tenable Network Security has extracted the preceding
description block directly from the SUSE 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://bugzilla.suse.com/show_bug.cgi?id=903649"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://bugzilla.suse.com/show_bug.cgi?id=932483"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://bugzilla.suse.com/show_bug.cgi?id=936695"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://bugzilla.suse.com/show_bug.cgi?id=938746"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://bugzilla.suse.com/show_bug.cgi?id=939932"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://bugzilla.suse.com/show_bug.cgi?id=943006"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://bugzilla.suse.com/show_bug.cgi?id=943010"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://bugzilla.suse.com/show_bug.cgi?id=945484"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://bugzilla.suse.com/show_bug.cgi?id=945493"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://bugzilla.suse.com/show_bug.cgi?id=947458"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://www.suse.com/security/cve/CVE-2015-4000/"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://www.suse.com/security/cve/CVE-2015-5352/"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://www.suse.com/security/cve/CVE-2015-5600/"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://www.suse.com/security/cve/CVE-2015-6563/"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://www.suse.com/security/cve/CVE-2015-6564/"
  );
  # https://www.suse.com/support/update/announcement/2015/suse-su-20151695-1.html
  script_set_attribute(
    attribute:"see_also",
    value:"http://www.nessus.org/u?a811b187"
  );
  script_set_attribute(
    attribute:"solution", 
    value:
"To install this SUSE Security Update use YaST online_update.
Alternatively you can run the command listed for your product :

SUSE Linux Enterprise Server 11-SP4 :

zypper in -t patch slessp4-openssh-12119=1

SUSE Linux Enterprise Desktop 11-SP4 :

zypper in -t patch sledsp4-openssh-12119=1

SUSE Linux Enterprise Debuginfo 11-SP4 :

zypper in -t patch dbgsp4-openssh-12119=1

To bring your system up-to-date, use 'zypper patch'."
  );
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:P/I:N/A:C");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/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:novell:suse_linux:openssh");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:suse_linux:openssh-askpass-gnome");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:suse_linux:openssh-fips");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:suse_linux:openssh-helpers");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:novell:suse_linux:11");

  script_set_attribute(attribute:"vuln_publication_date", value:"2015/05/21");
  script_set_attribute(attribute:"patch_publication_date", value:"2015/10/05");
  script_set_attribute(attribute:"plugin_publication_date", value:"2015/10/12");
  script_set_attribute(attribute:"in_the_news", value:"true");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"This script is Copyright (C) 2015-2019 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/cpu", "Host/SuSE/release", "Host/SuSE/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/SuSE/release");
if (isnull(release) || release !~ "^(SLED|SLES)") audit(AUDIT_OS_NOT, "SUSE");
os_ver = pregmatch(pattern: "^(SLE(S|D)\d+)", string:release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, "SUSE");
os_ver = os_ver[1];
if (! preg(pattern:"^(SLED11|SLES11)$", string:os_ver)) audit(AUDIT_OS_NOT, "SUSE SLED11 / SLES11", "SUSE " + os_ver);

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

cpu = get_kb_item("Host/cpu");
if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH);
if (cpu !~ "^i[3-6]86$" && "x86_64" >!< cpu && "s390x" >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, "SUSE " + os_ver, cpu);

sp = get_kb_item("Host/SuSE/patchlevel");
if (isnull(sp)) sp = "0";
if (os_ver == "SLES11" && (! preg(pattern:"^(4)$", string:sp))) audit(AUDIT_OS_NOT, "SLES11 SP4", os_ver + " SP" + sp);
if (os_ver == "SLED11" && (! preg(pattern:"^(4)$", string:sp))) audit(AUDIT_OS_NOT, "SLED11 SP4", os_ver + " SP" + sp);


flag = 0;
if (rpm_check(release:"SLES11", sp:"4", reference:"openssh-6.6p1-13.1")) flag++;
if (rpm_check(release:"SLES11", sp:"4", reference:"openssh-askpass-gnome-6.6p1-13.3")) flag++;
if (rpm_check(release:"SLES11", sp:"4", reference:"openssh-fips-6.6p1-13.1")) flag++;
if (rpm_check(release:"SLES11", sp:"4", reference:"openssh-helpers-6.6p1-13.1")) flag++;
if (rpm_check(release:"SLED11", sp:"4", cpu:"x86_64", reference:"openssh-6.6p1-13.1")) flag++;
if (rpm_check(release:"SLED11", sp:"4", cpu:"x86_64", reference:"openssh-askpass-gnome-6.6p1-13.3")) flag++;
if (rpm_check(release:"SLED11", sp:"4", cpu:"x86_64", reference:"openssh-helpers-6.6p1-13.1")) flag++;
if (rpm_check(release:"SLED11", sp:"4", cpu:"i586", reference:"openssh-6.6p1-13.1")) flag++;
if (rpm_check(release:"SLED11", sp:"4", cpu:"i586", reference:"openssh-askpass-gnome-6.6p1-13.3")) flag++;
if (rpm_check(release:"SLED11", sp:"4", cpu:"i586", reference:"openssh-helpers-6.6p1-13.1")) 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, "openssh");
}