Debian DLA-2284-1 : ksh security update

#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Debian Security Advisory DLA-2284-1. The text
# itself is copyright (C) Software in the Public Interest, Inc.
#

include('compat.inc');

if (description)
{
  script_id(138783);
  script_version("1.3");
  script_set_attribute(attribute:"plugin_modification_date", value:"2024/02/29");

  script_cve_id("CVE-2019-14868");

  script_name(english:"Debian DLA-2284-1 : ksh security update");

  script_set_attribute(attribute:"synopsis", value:
"The remote Debian host is missing a security update.");
  script_set_attribute(attribute:"description", value:
"A flaw was found in the way it evaluates certain environment
variables. An attacker could use this flaw to override or bypass
environment restrictions to execute shell commands. Services and
applications that allow remote unauthenticated attackers to provide
one of those environment variables could allow them to exploit this
issue remotely.

For Debian 9 stretch, this problem has been fixed in version
93u+20120801-3.1+deb9u1.

We recommend that you upgrade your ksh packages.

For the detailed security status of ksh please refer to its security
tracker page at: https://security-tracker.debian.org/tracker/ksh

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/2020/07/msg00015.html");
  script_set_attribute(attribute:"see_also", value:"https://packages.debian.org/source/stretch/ksh");
  script_set_attribute(attribute:"see_also", value:"https://security-tracker.debian.org/tracker/source-package/ksh");
  script_set_attribute(attribute:"solution", value:
"Upgrade the affected ksh package.");
  script_set_cvss_base_vector("CVSS2#AV:L/AC:L/Au:N/C:C/I:C/A:C");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2019-14868");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"false");

  script_set_attribute(attribute:"vuln_publication_date", value:"2020/04/02");
  script_set_attribute(attribute:"patch_publication_date", value:"2020/07/20");
  script_set_attribute(attribute:"plugin_publication_date", value:"2020/07/21");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:ksh");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:9.0");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

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

  script_copyright(english:"This script is Copyright (C) 2020-2024 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:"ksh", reference:"93u+20120801-3.1+deb9u1")) flag++;

if (flag)
{
  if (report_verbosity > 0) security_hole(port:0, extra:deb_report_get());
  else security_hole(0);
  exit(0);
}
else audit(AUDIT_HOST_NOT, "affected");