Information disclosure in Mozilla Firefox and Firefox ESR - CVE-2022-31742

Detailed vulnerability description

The vulnerability allows a remote attacker to gain access to potentially sensitive information.

The vulnerability exists due to an error when handling a large number of allowCredential entries. A remote attacker can trick the victim to visit a specially crafted website, launch a timing attack and detect the difference between invalid key handles and cross-origin key handles. Successful exploitation of the vulnerability can lead to cross-origin account linking in violation of WebAuthn goals.

How to mitigate CVE-2022-31742

Sources

• https://www.mozilla.org/en-US/security/advisories/mfsa2022-20/
• https://www.mozilla.org/en-US/security/advisories/mfsa2022-21/