A malicious webpage could have forced a Firefox for Android user into executing attacker-controlled JavaScript in the context of another domain, resulting in a Universal Cross-Site Scripting vulnerability. Note: This issue only affected Firefox for Android. Other operating systems are unaffected. Further details are being temporarily withheld to allow users an opportunity to update.. This vulnerability affects Firefox < 88.0.1 and Firefox for Android < 88.1.3.

References

• https://nvd.nist.gov/vuln/detail/CVE-2021-29953
• https://bugzilla.mozilla.org/show_bug.cgi?id=1701684
• https://www.mozilla.org/security/advisories/mfsa2021-20/