CVE-2021-42762

Name: CVE-2021-42762
Creator: NVD / NIST
Published: 2021-10-20T19:15:07.637+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 5.3/10EPSS 0.50%

Last modified Jun 17, 2026

CVE-2021-42762 is a medium-severity vulnerability rated 5.3/10 on the CVSS scale. BubblewrapLauncher.cpp in WebKitGTK and WPE WebKit before 2.34.1 allows a limited sandbox bypass that allows a sandboxed process to trick host processes into thinking the sandboxed process is not confined by the sandbox, by abusing VFS syscalls that manipulate its filesystem namespace. The impact is limited to host services that create UNIX sockets that WebKit mounts inside its sandbox, and the sandboxed process remains otherwise confined. EPSS estimates a 0.50% chance of exploitation in the next 30 days.

Description

BubblewrapLauncher.cpp in WebKitGTK and WPE WebKit before 2.34.1 allows a limited sandbox bypass that allows a sandboxed process to trick host processes into thinking the sandboxed process is not confined by the sandbox, by abusing VFS syscalls that manipulate its filesystem namespace. The impact is limited to host services that create UNIX sockets that WebKit mounts inside its sandbox, and the sandboxed process remains otherwise confined. NOTE: this is similar to CVE-2021-41133.

Metrics

CVSS 3.1

5.3/10

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L

EPSS Probability

0.50%

39.0th percentile

Probability of exploitation in the next 30 days. Learn more

Affected Software

Vendor	Product	Versions
Webkitgtk	Webkitgtk	< 2.34.1
Wpewebkit	Wpe Webkit	< 2.34.1
Fedoraproject	Fedora	33
Fedoraproject	Fedora	34
Fedoraproject	Fedora	35
Debian	Debian Linux	10.0
Debian	Debian Linux	11.0

References

http://www.openwall.com/lists/oss-security/2021/10/26/9Mailing List, Third Party Advisory
http://www.openwall.com/lists/oss-security/2021/10/27/1Mailing List, Third Party Advisory
http://www.openwall.com/lists/oss-security/2021/10/27/2Mailing List, Third Party Advisory
http://www.openwall.com/lists/oss-security/2021/10/27/4Mailing List, Third Party Advisory
https://bugs.webkit.org/show_bug.cgi?id=231479Exploit, Issue Tracking, Vendor Advisory
https://github.com/flatpak/flatpak/security/advisories/GHSA-67h7-w3jq-vh4qThird Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/H6MGXCX7P5AHWOQ6IRT477UKT7IS4DAD/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/M5J2LZQTDX53DNSKSGU7TQYCO2HKSTY4/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ON5SDVVPVPCAGFPW2GHYATZVZYLPW2L4/
https://www.debian.org/security/2021/dsa-4995Third Party Advisory
https://www.debian.org/security/2021/dsa-4996Third Party Advisory
http://www.openwall.com/lists/oss-security/2021/10/26/9Mailing List, Third Party Advisory
http://www.openwall.com/lists/oss-security/2021/10/27/1Mailing List, Third Party Advisory
http://www.openwall.com/lists/oss-security/2021/10/27/2Mailing List, Third Party Advisory
http://www.openwall.com/lists/oss-security/2021/10/27/4Mailing List, Third Party Advisory
https://bugs.webkit.org/show_bug.cgi?id=231479Exploit, Issue Tracking, Vendor Advisory
https://github.com/flatpak/flatpak/security/advisories/GHSA-67h7-w3jq-vh4qThird Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/H6MGXCX7P5AHWOQ6IRT477UKT7IS4DAD/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/M5J2LZQTDX53DNSKSGU7TQYCO2HKSTY4/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ON5SDVVPVPCAGFPW2GHYATZVZYLPW2L4/
https://www.debian.org/security/2021/dsa-4995Third Party Advisory
https://www.debian.org/security/2021/dsa-4996Third Party Advisory

Timeline

Published: Oct 20, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-42762?

How severe is CVE-2021-42762?

CVE-2021-42762 has a CVSS score of 5.3/10 (MEDIUM severity). The EPSS model estimates a 0.50% probability of exploitation in the next 30 days.

How do I fix CVE-2021-42762?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-42762?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST