CVE-2015-4495: Mozilla Firefox Same‑Origin Policy Bypass Allows Remote File Access
What It Is – A remote‑code‑execution‑type flaw in Mozilla Firefox that lets an attacker bypass the browser’s Same‑Origin Policy (SOP) and read arbitrary files on the victim machine or elevate privileges.
Exploitability – Publicly disclosed; proof‑of‑concept code exists. The vulnerability is rated High (CVSS ≈ 7.5). No known active exploit campaigns, but the risk is significant for any organization that permits unpatched browsers.
Affected Products – Mozilla Firefox versions prior to the security update released in 2015 (all desktop editions).
Why It Matters for Trust & Control Assurance
- SOP bypass undermines the access‑control guarantees browsers provide, exposing data that should be isolated by design.
- Continuous monitoring of browser patch levels and evidence of timely updates become essential audit artifacts for demonstrating due‑diligence.
- Enterprises are increasingly required to show a defensible audit trail for endpoint security controls; an unpatched Firefox breaks that chain of trust.
Recommended Actions
- Verify all endpoints run Firefox ≥ the version that includes the CVE‑2015‑4495 fix.
- Deploy a centralized patch‑management policy that captures proof of update for audit purposes.
- Enforce web‑browser hardening controls (e.g., disable legacy extensions, enable CSP, restrict file‑protocol usage).
- Add SOP‑bypass detection to your security monitoring rules and retain logs as evidence of control effectiveness.
Source: CISA KEV – CVE‑2015‑4495