CVE Vulnerabilities

CVE-2021-43536

Exposure of Sensitive Information to an Unauthorized Actor

Published: Dec 08, 2021 | Modified: Aug 08, 2023
CVSS 3.x
6.5
MEDIUM
Source:
NVD
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
CVSS 2.x
4.3 MEDIUM
AV:N/AC:M/Au:N/C:P/I:N/A:N
RedHat/V2
RedHat/V3
7.5 IMPORTANT
CVSS:3.0/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
Ubuntu
MEDIUM

Under certain circumstances, asynchronous functions could have caused a navigation to fail but expose the target URL. This vulnerability affects Thunderbird < 91.4.0, Firefox ESR < 91.4.0, and Firefox < 95.

Weakness

The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information.

Affected Software

Name Vendor Start Version End Version
Firefox Mozilla * 95.0 (excluding)
Firefox_esr Mozilla * 91.4.0 (excluding)
Thunderbird Mozilla * 91.4.0 (excluding)
Red Hat Enterprise Linux 7 RedHat firefox-0:91.4.0-1.el7_9 *
Red Hat Enterprise Linux 7 RedHat thunderbird-0:91.4.0-3.el7_9 *
Red Hat Enterprise Linux 8 RedHat firefox-0:91.4.0-1.el8_5 *
Red Hat Enterprise Linux 8 RedHat thunderbird-0:91.4.0-2.el8_5 *
Red Hat Enterprise Linux 8.1 Update Services for SAP Solutions RedHat firefox-0:91.4.0-1.el8_1 *
Red Hat Enterprise Linux 8.1 Update Services for SAP Solutions RedHat thunderbird-0:91.4.0-2.el8_1 *
Red Hat Enterprise Linux 8.2 Extended Update Support RedHat firefox-0:91.4.0-1.el8_2 *
Red Hat Enterprise Linux 8.2 Extended Update Support RedHat thunderbird-0:91.4.0-2.el8_2 *
Red Hat Enterprise Linux 8.4 Extended Update Support RedHat firefox-0:91.4.0-1.el8_4 *
Red Hat Enterprise Linux 8.4 Extended Update Support RedHat thunderbird-0:91.4.0-2.el8_4 *
Firefox Ubuntu bionic *
Firefox Ubuntu devel *
Firefox Ubuntu focal *
Firefox Ubuntu hirsute *
Firefox Ubuntu impish *
Firefox Ubuntu jammy *
Firefox Ubuntu kinetic *
Firefox Ubuntu lunar *
Firefox Ubuntu mantic *
Firefox Ubuntu noble *
Firefox Ubuntu trusty *
Firefox Ubuntu upstream *
Firefox Ubuntu xenial *
Firefox-esr Ubuntu trusty *
Firefox-esr Ubuntu upstream *
Firefox-esr Ubuntu xenial *
Mozjs38 Ubuntu bionic *
Mozjs38 Ubuntu esm-apps/bionic *
Mozjs38 Ubuntu upstream *
Mozjs52 Ubuntu bionic *
Mozjs52 Ubuntu esm-apps/focal *
Mozjs52 Ubuntu esm-infra/bionic *
Mozjs52 Ubuntu focal *
Mozjs52 Ubuntu upstream *
Mozjs68 Ubuntu focal *
Mozjs68 Ubuntu upstream *
Mozjs78 Ubuntu esm-apps/jammy *
Mozjs78 Ubuntu hirsute *
Mozjs78 Ubuntu impish *
Mozjs78 Ubuntu jammy *
Mozjs78 Ubuntu kinetic *
Mozjs78 Ubuntu lunar *
Mozjs78 Ubuntu upstream *
Thunderbird Ubuntu bionic *
Thunderbird Ubuntu devel *
Thunderbird Ubuntu focal *
Thunderbird Ubuntu hirsute *
Thunderbird Ubuntu impish *
Thunderbird Ubuntu jammy *
Thunderbird Ubuntu kinetic *
Thunderbird Ubuntu lunar *
Thunderbird Ubuntu mantic *
Thunderbird Ubuntu noble *
Thunderbird Ubuntu trusty *
Thunderbird Ubuntu upstream *
Thunderbird Ubuntu xenial *

Extended Description

There are many different kinds of mistakes that introduce information exposures. The severity of the error can range widely, depending on the context in which the product operates, the type of sensitive information that is revealed, and the benefits it may provide to an attacker. Some kinds of sensitive information include:

Information might be sensitive to different parties, each of which may have their own expectations for whether the information should be protected. These parties include:

Information exposures can occur in different ways:

It is common practice to describe any loss of confidentiality as an “information exposure,” but this can lead to overuse of CWE-200 in CWE mapping. From the CWE perspective, loss of confidentiality is a technical impact that can arise from dozens of different weaknesses, such as insecure file permissions or out-of-bounds read. CWE-200 and its lower-level descendants are intended to cover the mistakes that occur in behaviors that explicitly manage, store, transfer, or cleanse sensitive information.

Potential Mitigations

  • Compartmentalize the system to have “safe” areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area.
  • Ensure that appropriate compartmentalization is built into the system design, and the compartmentalization allows for and reinforces privilege separation functionality. Architects and designers should rely on the principle of least privilege to decide the appropriate time to use privileges and the time to drop privileges.

References