What’s Vulnerable › Vulnerabilities

CVE-2021-42762

• Severity: medium (CVSS 5.3 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.5% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2021-10-20 · updated 2026-06-17

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.

Affected products

• Debian Linux: 10.0, 11.0
• Fedoraproject Fedora: 33, 34, 35
• Webkit: before 2.34.1 — fixed in 2.34.1
• Wpewebkit Wpe Webkit: before 2.34.1 — fixed in 2.34.1

How to fix

Upgrade to a fixed version: Webkit 2.34.1; Wpewebkit Wpe Webkit 2.34.1. Check the vendor advisory for mitigations.

References

• http://www.openwall.com/lists/oss-security/2021/10/26/9
• http://www.openwall.com/lists/oss-security/2021/10/27/1
• http://www.openwall.com/lists/oss-security/2021/10/27/2
• http://www.openwall.com/lists/oss-security/2021/10/27/4
• https://bugs.webkit.org/show_bug.cgi?id=231479
• https://github.com/flatpak/flatpak/security/advisories/GHSA-67h7-w3jq-vh4q
• 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-4995
• https://www.debian.org/security/2021/dsa-4996
• http://www.openwall.com/lists/oss-security/2021/10/26/9

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