Mozilla Firefox Security Advisory (MFSA2021-52) - Linux

# SPDX-FileCopyrightText: 2022 Greenbone AG
# Some text descriptions might be excerpted from (a) referenced
# source(s), and are Copyright (C) by the respective right holder(s).
#
# SPDX-License-Identifier: GPL-2.0-only

CPE = "cpe:/a:mozilla:firefox";

if(description)
{
  script_oid("1.3.6.1.4.1.25623.1.2.1.2021.52");
  script_version("2026-07-02T06:53:57+0000");
  script_tag(name:"last_modification", value:"2026-07-02 06:53:57 +0000 (Thu, 02 Jul 2026)");
  script_tag(name:"creation_date", value:"2022-02-09 13:04:21 +0000 (Wed, 09 Feb 2022)");
  script_tag(name:"cvss_base", value:"6.8");
  script_tag(name:"cvss_base_vector", value:"AV:N/AC:M/Au:N/C:P/I:P/A:P");
  script_tag(name:"severity_vector", value:"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H");
  script_tag(name:"severity_origin", value:"NVD");
  script_tag(name:"severity_date", value:"2023-01-03 20:19:44 +0000 (Tue, 03 Jan 2023)");

  script_cve_id("CVE-2021-4129", "CVE-2021-43536", "CVE-2021-43537", "CVE-2021-43538", "CVE-2021-43539", "CVE-2021-43540", "CVE-2021-43541", "CVE-2021-43542", "CVE-2021-43543", "CVE-2021-43545", "CVE-2021-43546");

  script_name("Mozilla Firefox Security Advisory (MFSA2021-52) - Linux");

  script_category(ACT_GATHER_INFO);

  script_copyright("Copyright (C) 2022 Greenbone AG");
  script_family("General");
  script_dependencies("gb_firefox_detect_lin.nasl");
  script_mandatory_keys("mozilla/firefox/linux/detected");

  script_xref(name:"Advisory-ID", value:"MFSA2021-52");
  script_xref(name:"URL", value:"https://www.mozilla.org/en-US/security/advisories/mfsa2021-52/");
  script_xref(name:"URL", value:"https://bugzilla.mozilla.org/buglist.cgi?bug_id=1393362%2C1736046%2C1736751%2C1737009%2C1739372%2C1739421");
  script_xref(name:"URL", value:"https://bugzilla.mozilla.org/buglist.cgi?bug_id=1636629");
  script_xref(name:"URL", value:"https://bugzilla.mozilla.org/buglist.cgi?bug_id=1696685");
  script_xref(name:"URL", value:"https://bugzilla.mozilla.org/buglist.cgi?bug_id=1720926");
  script_xref(name:"URL", value:"https://bugzilla.mozilla.org/buglist.cgi?bug_id=1723281");
  script_xref(name:"URL", value:"https://bugzilla.mozilla.org/buglist.cgi?bug_id=1730120");
  script_xref(name:"URL", value:"https://bugzilla.mozilla.org/buglist.cgi?bug_id=1737751");
  script_xref(name:"URL", value:"https://bugzilla.mozilla.org/buglist.cgi?bug_id=1738237");
  script_xref(name:"URL", value:"https://bugzilla.mozilla.org/buglist.cgi?bug_id=1738418");
  script_xref(name:"URL", value:"https://bugzilla.mozilla.org/buglist.cgi?bug_id=1739091");
  script_xref(name:"URL", value:"https://bugzilla.mozilla.org/buglist.cgi?bug_id=1739683");

  script_tag(name:"summary", value:"The remote host is missing an update for Mozilla Firefox, announced via the advisory MFSA2021-52.");

  script_tag(name:"vuldetect", value:"Checks if a vulnerable package version is present on the target host.");

  script_tag(name:"insight", value:"CVE-2021-43536: URL leakage when navigating while executing asynchronous function

Under certain circumstances, asynchronous functions could have caused a navigation to fail but expose the target URL.

CVE-2021-43537: Heap buffer overflow when using structured clone

An incorrect type conversion of sizes from 64bit to 32bit integers allowed an attacker to corrupt memory leading to a potentially exploitable crash.

CVE-2021-43538: Missing fullscreen and pointer lock notification when requesting both

By misusing a race in our notification code, an attacker could have forcefully hidden the notification for pages that had received full screen and pointer lock access, which could have been used for spoofing attacks.

CVE-2021-43539: GC rooting failure when calling wasm instance methods

Failure to correctly record the location of live pointers across wasm instance calls resulted in a GC occurring within the call not tracing those live pointers. This could have led to a use-after-free causing a potentially exploitable crash.

CVE-2021-43540: WebExtensions could have installed persistent ServiceWorkers

WebExtensions with the correct permissions were able to create and install ServiceWorkers for third-party websites that would not have been uninstalled with the extension.

CVE-2021-43541: External protocol handler parameters were unescaped

When invoking protocol handlers for external protocols, a supplied parameter URL containing spaces was not properly escaped.

CVE-2021-43542: XMLHttpRequest error codes could have leaked the existence of an external protocol handler

Using XMLHttpRequest, an attacker could have identified installed applications by probing error messages for loading external protocols.

CVE-2021-43543: Bypass of CSP sandbox directive when embedding

Documents loaded with the CSP sandbox directive could have escaped the sandbox's script restriction by embedding additional content.

CVE-2021-43545: Denial of Service when using the Location API in a loop

Using the Location API in a loop could have caused severe application hangs and crashes.

CVE-2021-43546: Cursor spoofing could overlay user interface when native cursor is zoomed

It was possible to recreate previous cursor spoofing attacks against users with a zoomed native cursor.

CVE-2021-4129: Memory safety bugs fixed in Firefox 95 and Firefox ESR 91.4

Mozilla developers and community members Julian Hector, Randell Jesup, Gabriele Svelto, Tyson Smith, Christian Holler, and Masayuki Nakano reported memory safety bugs present in Firefox 94. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code.");

  script_tag(name:"affected", value:"Mozilla Firefox versions prior to 95.");

  script_tag(name:"solution", value:"The vendor has released an update. Please see the reference(s) for more information.");

  script_tag(name:"solution_type", value:"VendorFix");
  script_tag(name:"qod_type", value:"executable_version_unreliable");

  exit(0);
}

include("host_details.inc");
include("version_func.inc");

if (!infos = get_app_version_and_location(cpe: CPE, exit_no_version: TRUE))
  exit(0);

version = infos["version"];
location = infos["location"];

if (version_is_less(version: version, test_version: "95")) {
  report = report_fixed_ver(installed_version: version, fixed_version: "95", install_path: location);
  security_message(port: 0, data: report);
  exit(0);
}

exit(99);