CVE-2025-1018
Mozilla Firefox ≤ 135.0
Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:NSummary
CVE-2025-1018 is a medium-severity Improper Restriction of Rendered UI Layers or Frames (CWE-1021) vulnerability in Mozilla Firefox. Its CVSS base score is 5.3 (Medium).
Operationally, exploitation aligns with the MITRE ATT&CK technique Drive-by Compromise (T1189); ranked at the 34th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2025-1018 is a vulnerability in the fullscreen notification handling mechanism within Mozilla Firefox and Thunderbird. The issue occurs when the fullscreen notification is prematurely hidden upon quick re-requests for fullscreen by the user, enabling a potential spoofing attack. This flaw affects versions of Firefox and Thunderbird prior to 135 and is associated with CWE-1021, with a CVSS v3.1 base score of 5.3 (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N).
Remote attackers can exploit this vulnerability over the network with low attack complexity, requiring no privileges or specific user interaction beyond normal browser usage. Successful exploitation allows attackers to achieve low-impact integrity violations through spoofing, such as manipulating fullscreen notifications to deceive users.
Mozilla fixed this vulnerability in Firefox 135 and Thunderbird 135. Mitigation details are provided in security advisories MFSA 2025-07 and MFSA 2025-11, along with the Bugzilla entry at https://bugzilla.mozilla.org/show_bug.cgi?id=1910818.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2025-1973
Vulnerability Data
The fullscreen notification is prematurely hidden when fullscreen is re-requested quickly by the user. This could have been leveraged to perform a potential spoofing attack. This vulnerability was fixed in Firefox 135 and Thunderbird 135.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Secure SDLC practices directly require implementing frame-ancestors / X-Frame-Options controls that prevent this weakness.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Security testing can detect missing frame protections, but does not itself implement the control.
Web filtering can block or sandbox untrusted frames, but does not enforce application-level frame-busting or CSP.
Application security requirements can mandate frame-ancestors / X-Frame-Options, directly addressing UI redressing risks.
Secure architecture principles include isolation of UI layers and proper use of browser security controls.
Secure coding practices directly require implementation of frame-busting headers or CSP frame-ancestors directives.