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.
References (10)
Core 10
Core References
Vendor Advisory x_refsource_misc
https://www.mozilla.org/security/advisories/mfsa2021-49/
Vendor Advisory x_refsource_misc
https://www.mozilla.org/security/advisories/mfsa2021-50/
Vendor Advisory x_refsource_misc
https://www.mozilla.org/security/advisories/mfsa2021-48/
Issue Tracking, Permissions Required, Vendor Advisory x_refsource_misc
https://bugzilla.mozilla.org/show_bug.cgi?id=1729517
Third Party Advisory vendor-advisory
x_refsource_debian
https://www.debian.org/security/2021/dsa-5026
Mailing List, Third Party Advisory mailing-list
x_refsource_mlist
https://lists.debian.org/debian-lts-announce/2021/12/msg00030.html
Third Party Advisory vendor-advisory
x_refsource_debian
https://www.debian.org/security/2022/dsa-5034
Mailing List, Third Party Advisory mailing-list
x_refsource_mlist
https://lists.debian.org/debian-lts-announce/2022/01/msg00001.html
Third Party Advisory vendor-advisory
x_refsource_gentoo
https://security.gentoo.org/glsa/202202-03
Third Party Advisory vendor-advisory
x_refsource_gentoo
https://security.gentoo.org/glsa/202208-14
Scores
CVSS v3
10.0
EPSS
0.0108
EPSS Percentile
78.0%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
Details
CWE
CWE-863
Status
published
Products (6)
debian/debian_linux
9.0
debian/debian_linux
10.0
debian/debian_linux
11.0
mozilla/firefox
< 94.0
mozilla/firefox_esr
< 91.3
mozilla/thunderbird
< 91.3
Published
Dec 08, 2021
Tracked Since
Feb 18, 2026