SUSE SLES11 Security Update : openssh (SUSE-SU-2015:1840-1) (Logjam)

2015-11-02T00:00:00
ID SUSE_SU-2015-1840-1.NASL
Type nessus
Reporter Tenable
Modified 2018-11-29T00:00:00

Description

openssh was updated to fix four security issues.

These security issues were fixed :

  • CVE-2015-5352: The x11_open_helper function in channels.c in ssh in OpenSSH 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 in OpenSSH 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 (bsc#932483).

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

The update package also includes non-security fixes. See advisory for details.

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-2015:1840-1.
# The text itself is copyright (C) SUSE.
#

include("compat.inc");

if (description)
{
  script_id(86695);
  script_version("2.7");
  script_cvs_date("Date: 2018/11/29 12:03:38");

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

  script_name(english:"SUSE SLES11 Security Update : openssh (SUSE-SU-2015:1840-1) (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 four security issues.

These security issues were fixed :

  - CVE-2015-5352: The x11_open_helper function in
    channels.c in ssh in OpenSSH 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 in OpenSSH 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
    (bsc#932483).

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

The update package also includes non-security fixes. See advisory for
details.

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=673532"
  );
  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=905118"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://bugzilla.suse.com/show_bug.cgi?id=914309"
  );
  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://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/"
  );
  # https://www.suse.com/support/update/announcement/2015/suse-su-20151840-1.html
  script_set_attribute(
    attribute:"see_also",
    value:"http://www.nessus.org/u?e7517ec1"
  );
  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-SP2-LTSS :

zypper in -t patch slessp2-openssh-12168=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");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:suse_linux:openssh-askpass-gnome");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:novell:suse_linux:11");

  script_set_attribute(attribute:"patch_publication_date", value:"2015/10/19");
  script_set_attribute(attribute:"in_the_news", value:"true");
  script_set_attribute(attribute:"plugin_publication_date", value:"2015/11/02");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"This script is Copyright (C) 2015-2018 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 = eregmatch(pattern: "^(SLE(S|D)\d+)", string:release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, "SUSE");
os_ver = os_ver[1];
if (! ereg(pattern:"^(SLES11)$", string:os_ver)) audit(AUDIT_OS_NOT, "SUSE 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" && (! ereg(pattern:"^(2)$", string:sp))) audit(AUDIT_OS_NOT, "SLES11 SP2", os_ver + " SP" + sp);


flag = 0;
if (rpm_check(release:"SLES11", sp:"2", reference:"openssh-5.1p1-41.69.1")) flag++;
if (rpm_check(release:"SLES11", sp:"2", reference:"openssh-askpass-5.1p1-41.69.1")) flag++;
if (rpm_check(release:"SLES11", sp:"2", reference:"openssh-askpass-gnome-5.1p1-41.69.4")) 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");
}