CVE-2025-0239

When using Alt-Svc, ALPN did not properly validate certificates when the original server is redirecting to an insecure site. This vulnerability was fixed in Firefox 134, Firefox ESR 128.6, Thunderbird 134, and Thunderbird 128.6.

CVSS v3 4.0 MEDIUM

4.0^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 2.5 / Impact : 1.4

Attack Vector LOCAL

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact LOW

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://bugzilla.mozilla.org/show_bug.cgi?id=1929156	Issue Tracking Permissions Required
https://www.mozilla.org/security/advisories/mfsa2025-01/	Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2025-02/	Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2025-04/	Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2025-05/	Vendor Advisory
https://lists.debian.org/debian-lts-announce/2025/01/msg00004.html

Configurations

Configuration 1 (hide)

OR	cpe:2.3:a:mozilla:firefox:::::esr:::*
	cpe:2.3:a:mozilla:firefox::::::::
	cpe:2.3:a:mozilla:thunderbird::::::::
	cpe:2.3:a:mozilla:thunderbird::::::::

History

No history.

Information

Published : 2025-01-07 16:15

Updated : 2026-06-17 08:26

NVD link : CVE-2025-0239

Mitre link : CVE-2025-0239

CVE.ORG link : CVE-2025-0239

JSON object : View

Products Affected

mozilla

thunderbird
firefox

CWE

CWE-295

Improper Certificate Validation

{"id": "CVE-2025-0239", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2025-0239", "role": "CISA Coordinator", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "version": "2.0.3", "timestamp": "2025-01-08T16:33:42.534195Z"}}], "cvssMetricV31": [{"type": "Secondary", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 4.0, "attackVector": "LOCAL", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N", "integrityImpact": "LOW", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "NONE", "privilegesRequired": "NONE", "confidentialityImpact": "NONE"}, "impactScore": 1.4, "exploitabilityScore": 2.5}]}, "affected": [{"source": "security@mozilla.org", "affectedData": [{"vendor": "Mozilla", "product": "Firefox", "versions": [{"status": "unaffected", "version": "128.6", "versionType": "rpm", "lessThanOrEqual": "128.*"}, {"status": "unaffected", "version": "134", "versionType": "rpm", "lessThanOrEqual": "*"}]}, {"vendor": "Mozilla", "product": "Thunderbird", "versions": [{"status": "unaffected", "version": "128.6", "versionType": "rpm", "lessThanOrEqual": "128.*"}, {"status": "unaffected", "version": "134", "versionType": "rpm", "lessThanOrEqual": "*"}]}]}], "published": "2025-01-07T16:15:38.563", "references": [{"url": "https://bugzilla.mozilla.org/show_bug.cgi?id=1929156", "tags": ["Issue Tracking", "Permissions Required"], "source": "security@mozilla.org"}, {"url": "https://www.mozilla.org/security/advisories/mfsa2025-01/", "tags": ["Vendor Advisory"], "source": "security@mozilla.org"}, {"url": "https://www.mozilla.org/security/advisories/mfsa2025-02/", "tags": ["Vendor Advisory"], "source": "security@mozilla.org"}, {"url": "https://www.mozilla.org/security/advisories/mfsa2025-04/", "tags": ["Vendor Advisory"], "source": "security@mozilla.org"}, {"url": "https://www.mozilla.org/security/advisories/mfsa2025-05/", "tags": ["Vendor Advisory"], "source": "security@mozilla.org"}, {"url": "https://lists.debian.org/debian-lts-announce/2025/01/msg00004.html", "source": "af854a3a-2127-422b-91ae-364da2661108"}], "vulnStatus": "Modified", "weaknesses": [{"type": "Secondary", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "description": [{"lang": "en", "value": "CWE-295"}]}], "descriptions": [{"lang": "en", "value": "When using Alt-Svc, ALPN did not properly validate certificates when the original server is redirecting to an insecure site. This vulnerability was fixed in Firefox 134, Firefox ESR 128.6, Thunderbird 134, and Thunderbird 128.6."}, {"lang": "es", "value": "Al utilizar Alt-Svc, ALPN no valid\u00f3 correctamente los certificados cuando el servidor original redireccionaba a un sitio inseguro. Esta vulnerabilidad afecta a Firefox < 134 y Firefox ESR < 128.6."}], "lastModified": "2026-06-17T08:26:08.847", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:*", "vulnerable": true, "matchCriteriaId": "AEBB7F43-496D-4A67-8E9E-EEE29913B6DE", "versionEndExcluding": "128.6.0"}, {"criteria": "cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "4FDCA935-A68D-404E-A749-CA3845C709F0", "versionEndExcluding": "134.0"}, {"criteria": "cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "C92D62DE-A681-4B9D-9640-D12D04392A1B", "versionEndExcluding": "128.6.0"}, {"criteria": "cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "A633E231-80F8-4A92-BA69-B9BE5BE45D00", "versionEndExcluding": "134.0", "versionStartIncluding": "129.0"}], "operator": "OR"}]}], "sourceIdentifier": "security@mozilla.org"}