CVE-2021-42762

Exp

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.

Published: 2021-10-20 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2021-42762 is rated Exploit Available (50/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.01%). Core evidence: 1 public exploit reference(s) are indexed (Exploit-DB). Mandatory action: Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2021-42762

EDB-ID Source Kind Published Link
nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2021-42762

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2025-11-21 0.08% 0.01% -0.07%
2 2025-11-18 0.01% 0.08% +0.07%
3 2025-03-17 0.01%

Full EPSS history (12 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-42762

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.3 3.1 MEDIUM
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:L)
Might cause slowdowns, glitches, or partial disruption—not a full brick.
1.8 3.4 [email protected]
4.6 2.0 MEDIUM
AV:L/AC:L/Au:N/C:P/I:P/A:P Click to expand
Access vector (AV:L)
Requires local access to the target system.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:P)
Partial availability impact.
3.9 6.4 [email protected]

Weakness enumeration for CVE-2021-42762

OS Trackers for CVE-2021-42762

vendor priority summary link
alpine medium CVE-2021-42762: 1 source package rows (webkit2gtk); 5 state rows across 5 repos (3.17-community, 3.18-community, 3.19-community, 3.20-community, edge-community); fixed 5, open 0. https://security.alpinelinux.org/vuln/CVE-2021-42762
debian not yet assigned CVE-2021-42762 not yet assigned priority: Debian including 2 source packages (webkit2gtk, wpewebkit), 10 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 10. https://security-tracker.debian.org/tracker/CVE-2021-42762
gentoo high CVE-2021-42762: 1 GLSA(s) (202202-01), 1 atom(s) (net-libs/webkit-gtk); latest impact high. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2021-42762
redhat medium https://access.redhat.com/security/cve/CVE-2021-42762
suse high CVE-2021-42762 severity important: SUSE including 146 source package names (WebKit2GTK-4.1-lang-2.36.0-150400.2.13, WebKit2GTK-5.0-lang-2.36.0-150400.2.12, …), 363 product×package rows across 52 product lines (HPE Helion OpenStack 8, SUSE CaaS Platform 4.0, … (52 product lines)): Fixed 363. https://www.suse.com/security/cve/CVE-2021-42762/
ubuntu medium CVE-2021-42762 medium priority: Ubuntu including 5 source packages (qtwebkit-opensource-src, qtwebkit-source, webkit2gtk, webkitgtk, wpewebkit), 60 status rows across 12 suites (bionic, focal, hirsute, impish, jammy, kinetic, lunar, mantic, noble, trusty, upstream, xenial): DNE 27, ignored 20, released 9, needs-triage 3, not-affected 1. https://ubuntu.com/security/CVE-2021-42762

Affected software / configurations for CVE-2021-42762

Vendor Product Version Raw CPE
webkitgtk webkitgtk < 2.34.1 cpe:2.3:a:webkitgtk:webkitgtk:*:*:*:*:*:*:*:*
wpewebkit wpe_webkit < 2.34.1 cpe:2.3:a:wpewebkit:wpe_webkit:*:*:*:*:*:*:*:*
fedoraproject fedora 33 cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*
fedoraproject fedora 34 cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*
fedoraproject fedora 35 cpe:2.3:o:fedoraproject:fedora:35:*:*:*:*:*:*:*
debian debian_linux 10.0 cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*
debian debian_linux 11.0 cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*

References for CVE-2021-42762

URL Tags
http://www.openwall.com/lists/oss-security/2021/10/26/9 Mailing List Third Party Advisory
http://www.openwall.com/lists/oss-security/2021/10/27/1 Mailing List Third Party Advisory
http://www.openwall.com/lists/oss-security/2021/10/27/2 Mailing List Third Party Advisory
http://www.openwall.com/lists/oss-security/2021/10/27/4 Mailing List Third Party Advisory
https://bugs.webkit.org/show_bug.cgi?id=231479 Exploit Issue Tracking Vendor Advisory
https://github.com/flatpak/flatpak/security/advisories/GHSA-67h7-w3jq-vh4q Third 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-4995 Third Party Advisory
https://www.debian.org/security/2021/dsa-4996 Third Party Advisory
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