CVSS2
Attack Vector
NETWORK
Attack Complexity
MEDIUM
Authentication
NONE
Confidentiality Impact
PARTIAL
Integrity Impact
PARTIAL
Availability Impact
PARTIAL
AV:N/AC:M/Au:N/C:P/I:P/A:P
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
AI Score
Confidence
High
EPSS
Percentile
70.0%
The version of Firefox ESR installed on the remote Windows host is prior to 91.1. It is, therefore, affected by multiple vulnerabilities as referenced in the mfsa2021-41 advisory.
When delegating navigations to the operating system, Thunderbird would accept the mk
scheme which might allow attackers to launch pages and execute scripts in Internet Explorer in unprivileged mode. This bug only affects Thunderbird for Windows. Other operating systems are unaffected. (CVE-2021-38492)
Mozilla developers Tyson Smith, Christian Holler, and Gabriele Svelto reported memory safety bugs present in Thunderbird 78.13.0. 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. (CVE-2021-38495)
Note that Nessus has not tested for this issue but has instead relied only on the application’s self-reported version number.
#%NASL_MIN_LEVEL 70300
##
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Mozilla Foundation Security Advisory mfsa2021-41.
# The text itself is copyright (C) Mozilla Foundation.
##
include('deprecated_nasl_level.inc');
include('compat.inc');
if (description)
{
script_id(153105);
script_version("1.5");
script_set_attribute(attribute:"plugin_modification_date", value:"2023/12/01");
script_cve_id("CVE-2021-38492", "CVE-2021-38495");
script_xref(name:"IAVA", value:"2021-A-0405");
script_name(english:"Mozilla Firefox ESR < 91.1");
script_set_attribute(attribute:"synopsis", value:
"A web browser installed on the remote Windows host is affected by multiple vulnerabilities.");
script_set_attribute(attribute:"description", value:
"The version of Firefox ESR installed on the remote Windows host is prior to 91.1. It is, therefore, affected by multiple
vulnerabilities as referenced in the mfsa2021-41 advisory.
- When delegating navigations to the operating system, Thunderbird would accept the `mk` scheme which might
allow attackers to launch pages and execute scripts in Internet Explorer in unprivileged mode. This
bug only affects Thunderbird for Windows. Other operating systems are unaffected. (CVE-2021-38492)
- Mozilla developers Tyson Smith, Christian Holler, and Gabriele Svelto reported memory safety bugs present
in Thunderbird 78.13.0. 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. (CVE-2021-38495)
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://www.mozilla.org/en-US/security/advisories/mfsa2021-41/");
script_set_attribute(attribute:"solution", value:
"Upgrade to Mozilla Firefox ESR version 91.1 or later.");
script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:N/C:P/I:P/A:P");
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:R/S:U/C:H/I:H/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-2021-38495");
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:"2021/09/07");
script_set_attribute(attribute:"patch_publication_date", value:"2021/09/07");
script_set_attribute(attribute:"plugin_publication_date", value:"2021/09/08");
script_set_attribute(attribute:"plugin_type", value:"local");
script_set_attribute(attribute:"cpe", value:"cpe:/a:mozilla:firefox_esr");
script_set_attribute(attribute:"stig_severity", value:"I");
script_end_attributes();
script_category(ACT_GATHER_INFO);
script_family(english:"Windows");
script_copyright(english:"This script is Copyright (C) 2021-2023 and is owned by Tenable, Inc. or an Affiliate thereof.");
script_dependencies("mozilla_org_installed.nasl");
script_require_keys("Mozilla/Firefox/Version");
exit(0);
}
include('mozilla_version.inc');
var port = get_kb_item('SMB/transport');
if (!port) port = 445;
var installs = get_kb_list('SMB/Mozilla/Firefox/*');
if (isnull(installs)) audit(AUDIT_NOT_INST, 'Firefox');
mozilla_check_version(installs:installs, product:'firefox', esr:TRUE, fix:'91.1', min:'91.0.0', severity:SECURITY_WARNING);
CVSS2
Attack Vector
NETWORK
Attack Complexity
MEDIUM
Authentication
NONE
Confidentiality Impact
PARTIAL
Integrity Impact
PARTIAL
Availability Impact
PARTIAL
AV:N/AC:M/Au:N/C:P/I:P/A:P
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
AI Score
Confidence
High
EPSS
Percentile
70.0%