Debian DLA-1548-1 : libssh security update

#%NASL_MIN_LEVEL 70300
#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Debian Security Advisory DLA-1548-1. The text
# itself is copyright (C) Software in the Public Interest, Inc.
#

include('deprecated_nasl_level.inc');
include('compat.inc');

if (description)
{
  script_id(118214);
  script_version("1.7");
  script_set_attribute(attribute:"plugin_modification_date", value:"2024/07/30");

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

  script_name(english:"Debian DLA-1548-1 : libssh security update");

  script_set_attribute(attribute:"synopsis", value:
"The remote Debian host is missing a security 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.

For Debian 8 'Jessie', this problem has been fixed in version
0.6.3-4+deb8u3.

We recommend that you upgrade your libssh packages.

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/2018/10/msg00010.html");
  script_set_attribute(attribute:"see_also", value:"https://packages.debian.org/source/jessie/libssh");
  script_set_attribute(attribute:"solution", value:
"Upgrade the affected packages.");
  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:"2018/10/18");
  script_set_attribute(attribute:"plugin_publication_date", value:"2018/10/19");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:libssh-4");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:libssh-dbg");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:libssh-dev");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:libssh-doc");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:libssh-gcrypt-4");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:libssh-gcrypt-dev");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:8.0");
  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:"8.0", prefix:"libssh-4", reference:"0.6.3-4+deb8u3")) flag++;
if (deb_check(release:"8.0", prefix:"libssh-dbg", reference:"0.6.3-4+deb8u3")) flag++;
if (deb_check(release:"8.0", prefix:"libssh-dev", reference:"0.6.3-4+deb8u3")) flag++;
if (deb_check(release:"8.0", prefix:"libssh-doc", reference:"0.6.3-4+deb8u3")) flag++;
if (deb_check(release:"8.0", prefix:"libssh-gcrypt-4", reference:"0.6.3-4+deb8u3")) flag++;
if (deb_check(release:"8.0", prefix:"libssh-gcrypt-dev", reference:"0.6.3-4+deb8u3")) 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");