Amazon Linux 2 : python-virtualenv (ALAS-2026-4085)

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Amazon Linux 2 Security Advisory ALAS-2026-4085.
##

include('compat.inc');

if (description)
{
  script_id(377963);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/11/09");

  script_cve_id(
    "CVE-2026-113723",
    "CVE-2026-113725",
    "CVE-2026-113726",
    "CVE-2026-115586"
  );

  script_name(english:"Amazon Linux 2 : python-virtualenv (ALAS-2026-4085)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Amazon Linux 2 host is missing a security update.");
  script_set_attribute(attribute:"description", value:
"The version of python-virtualenv installed on the remote host is prior to 15.1.0-4. It is, therefore, affected by
multiple vulnerabilities as referenced in the ALAS2-2026-4085 advisory.

    virtualenv is a tool for creating isolated virtual python environments. Prior to 21.14.9, caller-supplied
    prompt text can become executable syntax in the bash activation prompt. An attacker must influence the
    value passed to virtualenv, and a user must subsequently activate the environment and draw the prompt.
    This vulnerability is fixed in 21.14.9. (CVE-2026-113723)

    virtualenv is a tool for creating isolated virtual python environments. Prior to 21.14.7, the bash
    activate script escapes the environment name for only one of the two passes bash makes over PS1, so a
    backslash in the name undoes the escaping and a name containing \$(...) runs as commands in the user's
    shell each time bash draws the prompt. This issue is fixed in version 21.14.7. (CVE-2026-113725)

    virtualenv is a tool for creating isolated virtual python environments. Prior to 21.13.0, the bash
    activate script that zsh also sources leaves the environment name unescaped; from 21.13.0 until 21.14.4,
    it escapes backslashes, dollar signs, and backticks only when BASH_VERSION is set, so zsh receives the raw
    value. The script assigns that value to PS1. In zsh with PROMPT_SUBST, an attacker-influenced environment
    directory, --prompt, or VIRTUALENV_PROMPT value containing command, parameter, or arithmetic expansion
    syntax can therefore execute commands in the user's shell each time the prompt is drawn. A percent sign is
    separately interpreted as a zsh prompt escape but does not by itself execute commands. Plain zsh with
    PROMPT_SUBST disabled and bash are not affected by this mechanism. This issue is fixed in version 21.14.4.
    (CVE-2026-113726)

    virtualenv is a tool for creating isolated virtual python environments. From 21.14.9 until 21.14.13, the
    bash bin/activate script can copy an attacker-controlled --prompt value into PS1 without escaping dollar
    signs or backticks when both promptvars and POSIX mode are disabled during activation. Re-enabling
    promptvars, running set -o posix, or starting an interactive child bash that inherits the exported PS1 can
    then expand command substitution in the stored VIRTUAL_ENV_PROMPT value and execute commands as the user
    who activates the environment. This issue is fixed in version 21.14.13. (CVE-2026-115586)

Tenable has extracted the preceding description block directly from the tested product security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version
number.");
  script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com//AL2/ALAS2-2026-4085.html");
  script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/faqs.html");
  script_set_attribute(attribute:"see_also", value:"https://explore.alas.aws.amazon.com/CVE-2026-113723.html");
  script_set_attribute(attribute:"see_also", value:"https://explore.alas.aws.amazon.com/CVE-2026-113725.html");
  script_set_attribute(attribute:"see_also", value:"https://explore.alas.aws.amazon.com/CVE-2026-113726.html");
  script_set_attribute(attribute:"see_also", value:"https://explore.alas.aws.amazon.com/CVE-2026-115586.html");
  script_set_attribute(attribute:"solution", value:
"Run 'yum update python-virtualenv' or
  or 'yum update --advisory ALAS2-2026-4085' to update your system.");
  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:N/UI:R/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:"cvss4_vector", value:"CVSS:4.0/AV:L/AC:H/AT:P/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N");
  script_set_attribute(attribute:"cvss4_threat_vector", value:"CVSS:4.0/E:U");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2026-113726");
  script_set_attribute(attribute:"cvss4_score_source", value:"CVE-2026-115586");

  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:"2026/10/20");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/11/09");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/11/09");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:python-virtualenv");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:amazon:linux:2");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

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

  script_copyright(english:"This script is Copyright (C) 2026 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("ssh_get_info2.nasl");
  script_require_keys("Host/local_checks_enabled", "Host/AmazonLinux/release", "Host/AmazonLinux/rpm-list");

  exit(0);
}

include("rpm2.inc");

if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);

var alas_release = get_kb_item("Host/AmazonLinux/release");
if (isnull(alas_release) || !strlen(alas_release)) audit(AUDIT_OS_NOT, "Amazon Linux");
var os_ver = pregmatch(pattern: "^AL(A|\d+|-\d+)", string:alas_release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, "Amazon Linux");
os_ver = os_ver[1];
if (os_ver != "2")
{
  if (os_ver == 'A') os_ver = 'AMI';
  audit(AUDIT_OS_NOT, "Amazon Linux 2", "Amazon Linux " + os_ver);
}

if (!get_kb_item("Host/AmazonLinux/rpm-list")) audit(AUDIT_PACKAGE_LIST_MISSING);

var pkgs = [
    {'reference':'python-virtualenv-15.1.0-4.amzn2.0.1', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE}
];

var flag = 0;
foreach var package_array ( pkgs ) {
  var reference = NULL;
  var _release = NULL;
  var sp = NULL;
  var _cpu = NULL;
  var el_string = NULL;
  var rpm_spec_vers_cmp = NULL;
  var epoch = NULL;
  var allowmaj = NULL;
  var exists_check = NULL;
  var cves = NULL;
  if (!empty_or_null(package_array['reference'])) reference = package_array['reference'];
  if (!empty_or_null(package_array['release'])) _release = package_array['release'];
  if (!empty_or_null(package_array['sp'])) sp = package_array['sp'];
  if (!empty_or_null(package_array['cpu'])) _cpu = package_array['cpu'];
  if (!empty_or_null(package_array['el_string'])) el_string = package_array['el_string'];
  if (!empty_or_null(package_array['rpm_spec_vers_cmp'])) rpm_spec_vers_cmp = package_array['rpm_spec_vers_cmp'];
  if (!empty_or_null(package_array['epoch'])) epoch = package_array['epoch'];
  if (!empty_or_null(package_array['allowmaj'])) allowmaj = package_array['allowmaj'];
  if (!empty_or_null(package_array['exists_check'])) exists_check = package_array['exists_check'];
  if (!empty_or_null(package_array['cves'])) cves = package_array['cves'];
  if (reference && _release && (!exists_check || rpm_exists(release:_release, rpm:exists_check))) {
    if (rpm_check(release:_release, sp:sp, cpu:_cpu, reference:reference, epoch:epoch, el_string:el_string, rpm_spec_vers_cmp:rpm_spec_vers_cmp, allowmaj:allowmaj, cves:cves)) flag++;
  }
}

if (flag)
{
  security_report_v4(
      port       : 0,
      severity   : SECURITY_HOLE,
      extra      : rpm_report_get()
  );
  exit(0);
}
else
{
  var tested = pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, "python-virtualenv");
}