Vulnerability identifier: #VU67503

Vulnerability risk: Medium

CVSSv3.1: 5.3 [CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2022-40956

CWE-ID: CWE-254

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Mozilla Firefox
Client/Desktop applications / Web browsers
Firefox ESR
Client/Desktop applications / Web browsers
Firefox for Android
Mobile applications / Apps for mobile phones

Vendor: Mozilla

Description

The vulnerability allows a remote attacker to bypass implemented security restrictions.

The vulnerability exists due to some requests may ignore the CSP's base-uri settings when handling HTML base element injection. A remote attacker can force the browser to accept the injected element's base instead of the original code, leading to Content Security Policy bypass.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Mozilla Firefox: 90.0 - 104.0.2

Firefox ESR: 102.0 - 102.2.0, 91.0 - 91.13.0

Firefox for Android: 100.1.0 - 104.2.0

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External links
http://www.mozilla.org/en-US/security/advisories/mfsa2022-40/
http://www.mozilla.org/en-US/security/advisories/mfsa2022-41/

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.