Debian DLA-425-1 : libssh security update

2016-02-24T00:00:00
ID DEBIAN_DLA-425.NASL
Type nessus
Reporter Tenable
Modified 2018-07-06T00:00:00

Description

Aris Adamantiadis of the libssh team discovered that libssh, an SSH2 protocol implementation used by many applications, did not generate sufficiently long Diffie-Hellman secrets.

This vulnerability could be exploited by an eavesdropper to decrypt and to intercept SSH sessions.

For the oldoldstable distribution (squeeze), this has been fixed in version 0.4.5-3+squeeze3.

For the oldstable (wheezy) and stable (jessie) distributions, this will be fixed soon.

NOTE: Tenable Network Security has extracted the preceding description block directly from the DLA 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 Debian Security Advisory DLA-425-1. The text
# itself is copyright (C) Software in the Public Interest, Inc.
#

include("compat.inc");

if (description)
{
  script_id(88913);
  script_version("2.8");
  script_cvs_date("Date: 2018/07/06 11:26:06");

  script_cve_id("CVE-2016-0739");

  script_name(english:"Debian DLA-425-1 : libssh security update");
  script_summary(english:"Checks dpkg output for the updated package.");

  script_set_attribute(
    attribute:"synopsis", 
    value:"The remote Debian host is missing a security update."
  );
  script_set_attribute(
    attribute:"description", 
    value:
"Aris Adamantiadis of the libssh team discovered that libssh, an SSH2
protocol implementation used by many applications, did not generate
sufficiently long Diffie-Hellman secrets.

This vulnerability could be exploited by an eavesdropper to decrypt
and to intercept SSH sessions.

For the oldoldstable distribution (squeeze), this has been fixed in
version 0.4.5-3+squeeze3.

For the oldstable (wheezy) and stable (jessie) distributions, this
will be fixed soon.

NOTE: Tenable Network Security has extracted the preceding description
block directly from the DLA 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://lists.debian.org/debian-lts-announce/2016/02/msg00017.html"
  );
  script_set_attribute(
    attribute:"solution", 
    value:"Upgrade the affected libssh package."
  );
  script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:N/C:P/I:N/A:N");
  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:H/I:N/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:debian:debian_linux:libssh");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:6.0");

  script_set_attribute(attribute:"patch_publication_date", value:"2016/02/23");
  script_set_attribute(attribute:"plugin_publication_date", value:"2016/02/24");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"This script is Copyright (C) 2016-2018 Tenable Network Security, Inc.");
  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:"6.0", prefix:"libssh", reference:"0.4.5-3+squeeze3")) 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");