Critical severity · published Dec 8, 2021
CVE-2021-38503
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
10.0
CVSS
4.1%
EPSS
No
On KEV
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 vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)4.1% · higher than 91% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
FI
Firefox · Mozilla
before 94.0 · source: NVD
DL
Debian Linux · Debian
9.0; 10.0; 11.0 · source: NVD
FE
Firefox Esr · Mozilla
before 91.3 · source: NVD
TH
Thunderbird · Mozilla
before 91.3 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-38503
CVE.org
https://www.cve.org/CVERecord?id=CVE-2021-38503
Issue Tracking
https://bugzilla.mozilla.org/show_bug.cgi?id=1729517
Mailing List
https://lists.debian.org/debian-lts-announce/2021/12/msg00030.html
Mailing List
https://lists.debian.org/debian-lts-announce/2022/01/msg00001.html
Third Party Advisory
https://security.gentoo.org/glsa/202202-03
Third Party Advisory
https://security.gentoo.org/glsa/202208-14
Third Party Advisory
https://www.debian.org/security/2021/dsa-5026
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