EulerOS 2.0 SP11 : gzip (EulerOS-SA-2026-4234)

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
##

include('compat.inc');

if (description)
{
  script_id(364788);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/10/14");

  script_cve_id("CVE-2026-41991", "CVE-2026-41992");
  script_xref(name:"IAVA", value:"2026-A-1097");

  script_name(english:"EulerOS 2.0 SP11 : gzip (EulerOS-SA-2026-4234)");

  script_set_attribute(attribute:"synopsis", value:
"The remote EulerOS host is missing multiple security updates.");
  script_set_attribute(attribute:"description", value:
"According to the versions of the gzip packages installed, the EulerOS installation on the remote host is affected by the
following vulnerabilities :

    GNU gzip contains a vulnerability in the gzexe utility related to insecure temporary file handling. When
    the mktemp utility is not available in the user's PATH, gzexe falls back to constructing a temporary file
    path based solely on the process ID (PID). This predictable filename is created without exclusive access
    or existence checks. A local attacker can pre-create the predicted temporary file path as a symbolic link
    pointing to an arbitrary file writable by the victim. When gzexe runs, it follows the symlink and
    overwrites the target file, resulting in a time-of-check to time-of-use (TOCTOU) condition that allows
    arbitrary file overwrite.(CVE-2026-41991)

    GNU gzip contains a global buffer overflow vulnerability in the LZH decompression logic caused by improper
    reuse of shared global state between different decompression formats within a single execution. GNU gzip
    maintains a global array that is shared across the LZ77, LZW, and LZH decompression routines and is not
    reinitialized between files processed in the same invocation. By decompressing a specially crafted LZW
    file followed by a specially crafted LZH file in a single gzip -d command, an attacker can poison the
    shared global state and subsequently trigger an outofbounds read in the LZH decoder. The LZH
    decompression logic follows stale values left in the shared array, causing reads past the end of the
    allocated global buffer.(CVE-2026-41992)

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

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version
number.");
  # https://developer.huaweicloud.com/ict/en/site-euleros/euleros/security-advisories/EulerOS-SA-2026-4234
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?910387b9");
  script_set_attribute(attribute:"solution", value:
"Update the affected gzip packages.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:C/I:N/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:N/A:N");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:P/RL:O/RC:C");
  script_set_attribute(attribute:"cvss4_vector", value:"CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N");
  script_set_attribute(attribute:"cvss4_threat_vector", value:"CVSS:4.0/E:P");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2026-41992");

  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:"2026/06/29");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/10/10");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/10/12");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:huawei:euleros:gzip");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:huawei:euleros:gzip-help");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:huawei:euleros:2.0");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_set_attribute(attribute:"stig_severity", value:"I");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Huawei 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/cpu", "Host/EulerOS/release", "Host/EulerOS/rpm-list", "Host/EulerOS/sp");
  script_exclude_keys("Host/EulerOS/uvp_version");

  exit(0);
}

include("rpm.inc");

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

var _release = get_kb_item("Host/EulerOS/release");
if (isnull(_release) || _release !~ "^EulerOS") audit(AUDIT_OS_NOT, "EulerOS");
var uvp = get_kb_item("Host/EulerOS/uvp_version");
if (_release !~ "^EulerOS release 2\.0(\D|$)") audit(AUDIT_OS_NOT, "EulerOS 2.0 SP11");

var sp = get_kb_item("Host/EulerOS/sp");
if (isnull(sp) || sp !~ "^(11)$") audit(AUDIT_OS_NOT, "EulerOS 2.0 SP11");

if (!empty_or_null(uvp)) audit(AUDIT_OS_NOT, "EulerOS 2.0 SP11", "EulerOS UVP " + uvp);

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

var cpu = get_kb_item("Host/cpu");
if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH);
if ("x86_64" >!< cpu && cpu !~ "^i[3-6]86$" && "aarch64" >!< cpu && "x86" >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, "EulerOS", cpu);
if ("x86_64" >!< cpu && cpu !~ "^i[3-6]86$" && "x86" >!< cpu) audit(AUDIT_ARCH_NOT, "i686 / x86_64", cpu);

var flag = 0;

var pkgs = [
  "gzip-1.11-1.h9.eulerosv2r11",
  "gzip-help-1.11-1.h9.eulerosv2r11"
];

foreach (var pkg in pkgs)
  if (rpm_check(release:"EulerOS-2.0", sp:"11", reference:pkg)) 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, "gzip");
}