Full Report
Mozilla has released updates to address a critical security flaw impacting its Firefox browser for Windows, merely days after Google patched a similar flaw in Chrome that came under active exploitation as a zero-day. The security vulnerability, CVE-2025-2857, has been described as a case of an incorrect handle that could lead to a sandbox escape. "Following the recent Chrome sandbox escape (
Analysis Summary
# Vulnerability: Firefox Incorrect Handle Leading to Sandbox Escape
## CVE Details
- CVE ID: CVE-2025-2857
- CVSS Score: N/A (Severity not explicitly defined in the text, but described as "critical")
- CWE: N/A (Specific CWE not provided, but related to IPC handling/sandbox escape)
## Affected Systems
- Products: Mozilla Firefox, Firefox ESR
- Versions: Prior to Firefox 136.0.4, Firefox ESR 115.21.1, and Firefox ESR 128.8.1.
- Configurations: N/A
## Vulnerability Description
This vulnerability is a sandbox escape flaw stemming from an incorrect handle issue within Firefox's Inter-Process Communication (IPC) code, similar to a recent Google Chrome vulnerability (CVE-2025-2783). A compromised child process can cause the parent process to return an "unintentionally powerful handle," which leads to the attacker breaking out of the browser sandbox.
## Exploitation
- Status: No evidence that CVE-2025-2857 has been exploited in the wild.
- Complexity: Implied to be high, as it requires breaking out of the sandbox.
- Attack Vector: Network (implied, as it relates to browser interaction).
## Impact
- Confidentiality: High (Potential for sandbox escape)
- Integrity: High (Potential for sandbox escape)
- Availability: High (Potential for sandbox escape leading to system compromise)
## Remediation
### Patches
- Firefox version 136.0.4
- Firefox ESR version 115.21.1
- Firefox ESR version 128.8.1
### Workarounds
- None explicitly mentioned in the summary. General recommendation is to update immediately.
## Detection
- No specific Indicators of Compromise (IoCs) are listed for this specific CVE.
- Detection would involve monitoring for unexpected process interactions or system calls indicative of a sandbox breach following a browser compromise.
## References
- Vendor Advisory: https://www.mozilla.org/en-US/security/advisories/mfsa2025-19/
- Related Information (Chrome CVE): https://thehackernews.com/2025/03/zero-day-alert-google-releases-chrome.html
- CISA KEV entry for the related Chrome vulnerability: https://www.cisa.gov/news-events/alerts/2025/03/27/cisa-adds-one-known-exploited-vulnerability-catalog