CVE-2021-38503: debian debian_linux Incorrect Authorization
CVSS: 10.0v3.1CriticalModified
AliasesUBUNTU-CVE-2021-38503DEBIAN-CVE-2021-38503
Published 08-12-2021Last modified 04-08-2024
Vulnerability summary
CVE-2021-38503 is a critical (CVSS 10.0) Incorrect Authorization vulnerability in debian debian_linux. EPSS estimates a 4.12% chance of exploitation in the next 30 days, higher than 90.6% of scored vulnerabilities.
CVSS score
10.0/10
010
Critical · v3.1 (NVD)EPSS score
4.12%
0%100%
Low · +0.29 pp in 30 daysKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded
Advisory lineage
Upstream 0 · Downstream 26 · Related 12DLA-2863-1DLA-2874-1DSA-5026-1DSA-5034-1MGASA-2021-0505MGASA-2021-0506OPENSUSE-SU-2021:1635-1OPENSUSE-SU-2021:3745-1OPENSUSE-SU-2021:4150-1OPENSUSE-SU-2024:11607-1OPENSUSE-SU-2024:11614-1OPENSUSE-SU-2024:14572-1RHSA-2021:4116RHSA-2021:4123RHSA-2021:4130RHSA-2021:4132RHSA-2021:4133RHSA-2021:4134RHSA-2021:4605RHSA-2021:4607SUSE-SU-2021:3651-1SUSE-SU-2021:3721-1SUSE-SU-2021:3745-1SUSE-SU-2021:4150-1USN-5131-1USN-5248-1
Timeline
- 08-12-2021PublishedVulnerability first disclosed.
- 04-08-2024Last modifiedVulnerability information updated.
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 metrics
4 scores · 3 sources · 2 versionsCritical 10.0Preferred score · NVD (NIST)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:HSourcesAll 3 agree
- OSV · UbuntuEcosystem advisory · calculated10.0CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
- OSV · DebianEcosystem advisory · calculated10.0CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
High 7.5Preferred score · NVD (NIST)
AV:N/AC:L/Au:N/C:P/I:P/A:PSourcesSingle source
EPSS trend
Probability
4.12%
Chance of exploitation in the next 30 days
Percentile
91%
Versus all other CVEs
30-day change
+0.29 pp
From 3.83% on 19-09-2026
19-09-202619-10-2026
EPSS score4.12%
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Ubuntu6 products
- firefox< 94.0+build3-0ubuntu0.18.04.1 | < 94.0+build3-0ubuntu0.20.04.1 | < 94.0+build3-0ubuntu1
- mozjs38All versions (No fix recorded)
- mozjs52All versions (No fix recorded)
- mozjs68All versions (No fix recorded)
- mozjs78All versions (No fix recorded)
Debian3 products
- firefox-esr< 91.3.0esr-1
- thunderbird< 1:91.3.0-1
- debian_linuxEOL9.0 | 10.0 | 11.0
Mozilla3 products
- firefox≥ unspecified, < 94 | < 94.0
- firefox_esr≥ unspecified, < 91.3 | < 91.3
- thunderbird≥ unspecified, < 91.3 | < 91.3
3 vendors · 12 products
References
18 links- bugzilla.mozilla.org/show_bug.cgi?id=1729517X Refsource MISCIssue TrackingPermissions RequiredVendor Advisory
- lists.debian.org/debian-lts-announce/2021/12/msg00030.htmlMailing ListX Refsource MLISTThird Party Advisory
- lists.debian.org/debian-lts-announce/2022/01/msg00001.htmlMailing ListX Refsource MLISTThird Party Advisory