CVE-2023-29540

Using a redirect embedded into <code>sourceMappingUrls</code> could allow for navigation to external protocol links in sandboxed iframes without <code>allow-top-navigation-to-custom-protocols</code>. This vulnerability affects Firefox for Android < 112, Firefox < 112, and Focus for Android < 112.

Published: 2023-06-02 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2023-29540 is rated Low Risk (37.4/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.16%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.

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

Exploit prediction scoring system (EPSS) score for CVE-2023-29540

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 2026-05-31 0.14% 0.16% +0.02%
2 2026-04-26 0.17% 0.14% -0.03%
3 2026-02-25 0.17%

Full EPSS history (5 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2023-29540

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.1 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
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:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
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:N)
Service keeps running; no real outage angle.
2.8 2.7 [email protected]

Weakness enumeration for CVE-2023-29540

OS Trackers for CVE-2023-29540

vendor priority summary link
alpine medium CVE-2023-29540: 1 source package rows (firefox); 74 state rows across 2 repos (3.22-community, edge-community); fixed 0, open 74. https://security.alpinelinux.org/vuln/CVE-2023-29540
debian not yet assigned CVE-2023-29540 not yet assigned priority: Debian including 1 source packages (firefox), 1 status rows across 1 suites (sid): resolved 1. https://security-tracker.debian.org/tracker/CVE-2023-29540
gentoo high CVE-2023-29540: 1 GLSA(s) (202305-35), 2 atom(s) (www-client/firefox, www-client/firefox-bin); latest impact high. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2023-29540
ubuntu medium CVE-2023-29540 medium priority: Ubuntu including 7 source packages (firefox, mozjs38, …), 70 status rows across 10 suites (bionic, focal, jammy, kinetic, lunar, mantic, noble, trusty, upstream, xenial): DNE 38, ignored 19, not-affected 9, released 3, needs-triage 1. https://ubuntu.com/security/CVE-2023-29540

Affected software / configurations for CVE-2023-29540

Vendor Product Version Raw CPE
mozilla firefox < 112.0 cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*
mozilla firefox < 112.0 cpe:2.3:a:mozilla:firefox:*:*:*:*:*:android:*:*
mozilla focus < 112.0 cpe:2.3:a:mozilla:focus:*:*:*:*:*:android:*:*

References for CVE-2023-29540

URL Tags
https://bugzilla.mozilla.org/show_bug.cgi?id=1790542 Issue Tracking Permissions Required Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2023-13/ Vendor Advisory
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