Debian DSA-4322-1 : libssh - security update

#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were  
# extracted from Debian Security Advisory DSA-4322. The text 
# itself is copyright (C) Software in the Public Interest, Inc.
#

include('compat.inc');

if (description)
{
  script_id(118180);
  script_version("1.8");
  script_set_attribute(attribute:"plugin_modification_date", value:"2024/07/30");

  script_cve_id("CVE-2018-10933");
  script_xref(name:"DSA", value:"4322");
  script_xref(name:"IAVA", value:"2018-A-0347-S");

  script_name(english:"Debian DSA-4322-1 : libssh - security update");

  script_set_attribute(attribute:"synopsis", value:
"The remote Debian host is missing a security-related update.");
  script_set_attribute(attribute:"description", value:
"Peter Winter-Smith of NCC Group discovered that libssh, a tiny C SSH
library, contains an authentication bypass vulnerability in the server
code. An attacker can take advantage of this flaw to successfully
authenticate without any credentials by presenting the server an
SSH2_MSG_USERAUTH_SUCCESS message in place of the
SSH2_MSG_USERAUTH_REQUEST message which the server would expect to
initiate authentication.");
  script_set_attribute(attribute:"see_also", value:"https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=911149");
  script_set_attribute(attribute:"see_also", value:"https://security-tracker.debian.org/tracker/source-package/libssh");
  script_set_attribute(attribute:"see_also", value:"https://packages.debian.org/source/stretch/libssh");
  script_set_attribute(attribute:"see_also", value:"https://www.debian.org/security/2018/dsa-4322");
  script_set_attribute(attribute:"solution", value:
"Upgrade the libssh packages.

For the stable distribution (stretch), this problem has been fixed in
version 0.7.3-2+deb9u1.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:N");
  script_set_cvss_temporal_vector("CVSS2#E:POC/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:P/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2018-10933");

  script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"true");
  script_set_attribute(attribute:"in_the_news", value:"true");

  script_set_attribute(attribute:"patch_publication_date", value:"2018/10/17");
  script_set_attribute(attribute:"plugin_publication_date", value:"2018/10/18");

  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:9.0");
  script_set_attribute(attribute:"stig_severity", value:"I");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Debian Local Security Checks");

  script_copyright(english:"This script is Copyright (C) 2018-2024 and is owned by Tenable, Inc. or an Affiliate thereof.");

  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:"9.0", prefix:"libssh-4", reference:"0.7.3-2+deb9u1")) flag++;
if (deb_check(release:"9.0", prefix:"libssh-dev", reference:"0.7.3-2+deb9u1")) flag++;
if (deb_check(release:"9.0", prefix:"libssh-doc", reference:"0.7.3-2+deb9u1")) flag++;
if (deb_check(release:"9.0", prefix:"libssh-gcrypt-4", reference:"0.7.3-2+deb9u1")) flag++;
if (deb_check(release:"9.0", prefix:"libssh-gcrypt-dev", reference:"0.7.3-2+deb9u1")) 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");