#VU61104 Time-of-check Time-of-use (TOCTOU) Race Condition in Mozilla Firefox and Firefox ESR


Published: 2022-03-08

Vulnerability identifier: #VU61104

Vulnerability risk: Medium

CVSSv3.1: 4.6 [CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2022-26387

CWE-ID: CWE-367

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Mozilla Firefox
Client/Desktop applications / Web browsers
Firefox ESR
Client/Desktop applications / Web browsers

Vendor: Mozilla

Description

The vulnerability allows a remote attacker to perform spoofing attack.

The vulnerability exists due to a race condition when verifying signatures during Firefox add-on installation. A remote attacker can replace the underlying add-on file while the user was confirming the prompt and install a malicious add-on on the system.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Mozilla Firefox: 90.0 - 97.0.2

Firefox ESR: 91.0 - 91.6.1


External links
http://www.mozilla.org/en-US/security/advisories/mfsa2022-10/
http://www.mozilla.org/en-US/security/advisories/mfsa2022-11/


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.


Latest bulletins with this vulnerability