Vulnerability Name:

CVE-2021-43540 (CCN-214735)

Assigned:2021-12-07
Published:2021-12-07
Updated:2022-07-12
Summary: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. This vulnerability affects Firefox < 95.
CVSS v3 Severity:6.5 Medium (CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N)
5.7 Medium (Temporal CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N/E:U/RL:O/RC:C)
Exploitability Metrics:Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): None
User Interaction (UI): Required
Scope:Scope (S): Unchanged
Impact Metrics:Confidentiality (C): None
Integrity (I): High
Availibility (A): None
6.5 Medium (CCN CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N)
5.7 Medium (CCN Temporal CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N/E:U/RL:O/RC:C)
Exploitability Metrics:Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): None
User Interaction (UI): Required
Scope:Scope (S): Unchanged
Impact Metrics:Confidentiality (C): None
Integrity (I): High
Availibility (A): None
CVSS v2 Severity:4.3 Medium (CVSS v2 Vector: AV:N/AC:M/Au:N/C:N/I:P/A:N)
Exploitability Metrics:Access Vector (AV): Network
Access Complexity (AC): Medium
Authentication (Au): None
Impact Metrics:Confidentiality (C): None
Integrity (I): Partial
Availibility (A): None
6.8 Medium (CCN CVSS v2 Vector: AV:N/AC:L/Au:S/C:N/I:C/A:N)
Exploitability Metrics:Access Vector (AV): Network
Access Complexity (AC): Low
Athentication (Au): Single_Instance
Impact Metrics:Confidentiality (C): None
Integrity (I): Complete
Availibility (A): None
Vulnerability Type:CWE-noinfo
Vulnerability Consequences:Bypass Security
References:Source: MITRE
Type: CNA
CVE-2021-43540

Source: MISC
Type: Issue Tracking, Permissions Required, Vendor Advisory
https://bugzilla.mozilla.org/show_bug.cgi?id=1636629

Source: XF
Type: UNKNOWN
firefox-cve202143540-sec-bypass(214735)

Source: GENTOO
Type: Third Party Advisory
GLSA-202202-03

Source: CCN
Type: Mozilla Foundation Security Advisory 2021-52
Security Vulnerabilities fixed in Firefox 95

Source: MISC
Type: Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2021-52/

Vulnerable Configuration:Configuration 1:
  • cpe:/a:mozilla:firefox:*:*:*:*:*:*:*:* (Version < 95.0)

    • * Denotes that component is vulnerable
    Oval Definitions
    Definition IDClassTitleLast Modified
    oval:org.opensuse.security:def:111902
    P
    		MozillaFirefox-95.0-1.1 on GA media (Moderate)
    2022-01-17
    BACK
    mozilla firefox *