Mozilla has released emergency updates to patch a critical sandbox escape vulnerability (CVE-2025-2857) in Firefox for Windows, mirroring a similar zero-day flaw (CVE-2025-2783) recently exploited in Chrome. The vulnerability, stemming from incorrect IPC handle management, could allow attackers to bypass browser sandbox protections. This comes days after Google addressed its actively exploited flaw, which was linked to an espionage campaign targeting Russian entities.
TL;DR Summary
- Firefox Vulnerability (CVE-2025-2857): Windows-specific sandbox escape via IPC handle mismanagement. No known exploitation yet.
- Chrome Zero-Day (CVE-2025-2783): Actively exploited in Operation ForumTroll, now listed in CISA’s KEV catalog.
- Affected Versions: Firefox 136.0.4, ESR 115.21.1/128.8.1.
- Mitigation: Immediate patching required; federal agencies must comply by April 17, 2025.
Technical Analysis
The Firefox flaw involves a handle leak in the Inter-Process Communication (IPC) layer, allowing malicious code to escape the browser’s sandbox and execute arbitrary code with elevated privileges. This mirrors Chrome’s CVE-2025-2783, which was chained with an undisclosed RCE for full system compromise. Both vulnerabilities exploit Windows-specific mechanisms, underscoring the platform’s heightened risk profile for sandbox escapes.
Historical context reveals a pattern: Firefox’s 2024 emergency patch (CVE-2024-9680) was similarly exploited in the wild, often paired with Windows privilege escalation bugs. The recurrence of IPC-related flaws suggests systemic issues in browser architecture.
Exploitation Landscape
Chrome’s zero-day was weaponized in Operation ForumTroll, a campaign targeting Russian entities via phishing lures. The Hacker News notes parallels between the two browser vulnerabilities, suggesting shared attack vectors^3. Separately, Counter-Strike 2 players were targeted using “browser-in-the-browser” phishing techniques, though no direct link to these flaws has been confirmed^4.
Mitigation and Relevance
For enterprises, patching is urgent: CISA mandates federal agencies to apply fixes by April 17, 2025^2. Developers should audit IPC handle management in custom applications, particularly those using sandboxing. Monitoring for suspicious child process creation is recommended, as sandbox escapes often spawn new processes.
Conclusion
The rapid succession of these vulnerabilities highlights persistent challenges in browser security. While Mozilla’s proactive patch is commendable, the similarity to Chrome’s exploited flaw raises questions about shared code risks. Ongoing vigilance and layered defenses remain critical.
References
- Mozilla Advisory. [Accessed March 2025].
- CISA KEV Catalog. [Accessed March 2025].
- The Hacker News. [Accessed March 2025].
- CyberInsider. [Accessed March 2025].
