CVE-2023-29542

A newline in a filename could have been used to bypass the file extension security mechanisms that replace malicious file extensions such as .lnk with .download. This could have led to accidental execution of malicious code. *This bug only affects Firefox and Thunderbird on Windows. Other versions of Firefox and Thunderbird are unaffected.* This vulnerability affects Firefox < 112, Firefox ESR < 102.10, and Thunderbird < 102.10.

Published: 2023-06-19 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2023-29542 is rated Moderate Risk (59.7/100): CVSS Critical severity, with medium exploitation likelihood (EPSS 0.94%). Mandatory action: Review affected assets and schedule remediation.

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-2023-29542

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 2026-06-15 0.12% 0.94% +0.82%
2 2025-11-21 2.03% 0.12% -1.91%
3 2025-11-18 2.03%

Full EPSS history (14 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2023-29542

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
9.8 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H 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: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:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
3.9 5.9 [email protected]
9.8 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H 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: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:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
3.9 5.9 134c704f-9b21-4f2e-91b3-4a467353bcc0

Weakness enumeration for CVE-2023-29542

OS Trackers for CVE-2023-29542

vendor priority summary link
alpine CVE-2023-29542: 3 source package rows (firefox, firefox-esr, thunderbird); 126 state rows across 6 repos (3.18-community, 3.19-community, 3.20-community, 3.21-community, 3.22-community, edge-community); fixed 8, open 118. https://security.alpinelinux.org/vuln/CVE-2023-29542
debian unimportant CVE-2023-29542 unimportant priority: Debian including 3 source packages (firefox, firefox-esr, thunderbird), 11 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 11. https://security-tracker.debian.org/tracker/CVE-2023-29542
redhat medium https://access.redhat.com/security/cve/CVE-2023-29542
ubuntu medium CVE-2023-29542 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 39, ignored 17, not-affected 14. https://ubuntu.com/security/CVE-2023-29542

Affected software / configurations for CVE-2023-29542

Vendor Product Version Raw CPE
mozilla firefox < 112.0 cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*
mozilla firefox_esr < 102.10 cpe:2.3:a:mozilla:firefox_esr:*:*:*:*:*:*:*:*
mozilla thunderbird < 102.10 cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*

References for CVE-2023-29542

cvelogic Threat Intelligence