Debian dla-4557 : pypy-pyasn1 - security update

#%NASL_MIN_LEVEL 80900
#
# (C) Tenable, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Debian Security Advisory dla-4557. The text
# itself is copyright (C) Software in the Public Interest, Inc.
#

include('compat.inc');

if (description)
{
  script_id(311489);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/05/02");

  script_cve_id("CVE-2026-30922");

  script_name(english:"Debian dla-4557 : pypy-pyasn1 - security update");

  script_set_attribute(attribute:"synopsis", value:
"The remote Debian host is missing a security-related update.");
  script_set_attribute(attribute:"description", value:
"The remote Debian 11 host has packages installed that are affected by a vulnerability as referenced in the dla-4557
advisory.

    -------------------------------------------------------------------------
    Debian LTS Advisory DLA-4557-1                [email protected]
    https://www.debian.org/lts/security/                       Emmanuel Arias
    May 01, 2026                                  https://wiki.debian.org/LTS
    -------------------------------------------------------------------------

    Package        : pyasn1
    Version        : 0.4.8-1+deb11u2
    CVE ID         : CVE-2026-30922
    Debian Bug     : 1131371

    It was discovered that pyasn1, a generic ASN.1 library for Python, is vulnerable
    to a Denial of Service (DoS) attack caused by uncontrolled recursion when
    decoding ASN.1 data with deeply nested structures. This vulnerability can force
    the decoder to recursively call itself until the Python interpreter crashes with a
    `RecursionError` or consumes all available memory, crashing the host application.

    For Debian 11 bullseye, this problem has been fixed in version
    0.4.8-1+deb11u2.

    We recommend that you upgrade your pyasn1 packages.

    For the detailed security status of pyasn1 please refer to
    its security tracker page at:
    https://security-tracker.debian.org/tracker/pyasn1

    Further information about Debian LTS security advisories, how to apply
    these updates to your system and frequently asked questions can be
    found at: https://wiki.debian.org/LTS
    Attachment:
    signature.asc
    Description: PGP signature

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

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version
number.");
  script_set_attribute(attribute:"see_also", value:"https://security-tracker.debian.org/tracker/source-package/pyasn1");
  script_set_attribute(attribute:"see_also", value:"https://security-tracker.debian.org/tracker/CVE-2026-30922");
  script_set_attribute(attribute:"see_also", value:"https://packages.debian.org/source/bullseye/pyasn1");
  script_set_attribute(attribute:"solution", value:
"Upgrade the pypy-pyasn1 packages.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:C");
  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:N/I:N/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:P/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2026-30922");

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

  script_set_attribute(attribute:"vuln_publication_date", value:"2026/03/17");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/05/01");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/05/02");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:pypy-pyasn1");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:python-pyasn1-doc");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:python3-pyasn1");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:11.0");
  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) 2026 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('debian_package.inc');

if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
if (!get_kb_item("Host/Debian/dpkg-l")) audit(AUDIT_PACKAGE_LIST_MISSING);

var debian_release = get_kb_item('Host/Debian/release');
if ( isnull(debian_release) ) audit(AUDIT_OS_NOT, 'Debian');
debian_release = chomp(debian_release);
if (! preg(pattern:"^(11)\.[0-9]+", string:debian_release)) audit(AUDIT_OS_NOT, 'Debian 11.0', 'Debian ' + debian_release);
var cpu = get_kb_item('Host/cpu');
if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH);
if ('x86_64' >!< cpu && cpu !~ "^i[3-6]86$" && 'aarch64' >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'Debian', cpu);

var pkgs = [
    {'release': '11.0', 'prefix': 'pypy-pyasn1', 'reference': '0.4.8-1+deb11u2'},
    {'release': '11.0', 'prefix': 'python-pyasn1-doc', 'reference': '0.4.8-1+deb11u2'},
    {'release': '11.0', 'prefix': 'python3-pyasn1', 'reference': '0.4.8-1+deb11u2'}
];

var flag = 0;
foreach package_array ( pkgs ) {
  var _release = NULL;
  var prefix = NULL;
  var reference = NULL;
  if (!empty_or_null(package_array['release'])) _release = package_array['release'];
  if (!empty_or_null(package_array['prefix'])) prefix = package_array['prefix'];
  if (!empty_or_null(package_array['reference'])) reference = package_array['reference'];
  if (_release && prefix && reference) {
    if (deb_check(release:_release, prefix:prefix, reference:reference)) flag++;
  }
}

if (flag)
{
  security_report_v4(
    port       : 0,
    severity   : SECURITY_HOLE,
    extra      : deb_report_get()
  );
  exit(0);
}
else
{
  var tested = deb_pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, 'pypy-pyasn1 / python-pyasn1-doc / python3-pyasn1');
}