Vulnerability Description
The iframe sandbox rules were not correctly applied to XSLT stylesheets, allowing an iframe to bypass restrictions such as executing scripts or navigating the top-level frame. This vulnerability affects Firefox < 94, Thunderbird < 91.3, and Firefox ESR < 91.3.
CVSS Score
CRITICAL
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Mozilla | Firefox | < 94.0 |
| Mozilla | Firefox Esr | < 91.3 |
| Mozilla | Thunderbird | < 91.3 |
| Debian | Debian Linux | 9.0 |
Related Weaknesses (CWE)
References
- https://bugzilla.mozilla.org/show_bug.cgi?id=1729517Issue TrackingPermissions RequiredVendor Advisory
- https://lists.debian.org/debian-lts-announce/2021/12/msg00030.htmlMailing ListThird Party Advisory
- https://lists.debian.org/debian-lts-announce/2022/01/msg00001.htmlMailing ListThird Party Advisory
- https://security.gentoo.org/glsa/202202-03Third Party Advisory
- https://security.gentoo.org/glsa/202208-14Third Party Advisory
- https://www.debian.org/security/2021/dsa-5026Third Party Advisory
- https://www.debian.org/security/2022/dsa-5034Third Party Advisory
- https://www.mozilla.org/security/advisories/mfsa2021-48/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2021-49/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2021-50/Vendor Advisory
- https://bugzilla.mozilla.org/show_bug.cgi?id=1729517Issue TrackingPermissions RequiredVendor Advisory
- https://lists.debian.org/debian-lts-announce/2021/12/msg00030.htmlMailing ListThird Party Advisory
- https://lists.debian.org/debian-lts-announce/2022/01/msg00001.htmlMailing ListThird Party Advisory
- https://security.gentoo.org/glsa/202202-03Third Party Advisory
- https://security.gentoo.org/glsa/202208-14Third Party Advisory
FAQ
What is CVE-2021-38503?
CVE-2021-38503 is a vulnerability with a CVSS score of 10.0 (CRITICAL). The iframe sandbox rules were not correctly applied to XSLT stylesheets, allowing an iframe to bypass restrictions such as executing scripts or navigating the top-level frame. This vulnerability affec...
How severe is CVE-2021-38503?
CVE-2021-38503 has been rated CRITICAL with a CVSS base score of 10.0/10. This is considered a critical vulnerability requiring immediate attention.
Is there a patch for CVE-2021-38503?
Check the references section above for vendor advisories and patch information. Affected products include: Mozilla Firefox, Mozilla Firefox Esr, Mozilla Thunderbird, Debian Debian Linux.