CVE-2025-14860: Mozilla Firefox Use-After-Free Flaw

CVE-2025-14860 Overview

CVE-2025-14860 is a critical use-after-free vulnerability in the Disability Access APIs component of Mozilla Firefox. This memory corruption flaw occurs when the browser improperly handles memory associated with accessibility features, potentially allowing attackers to execute arbitrary code in the context of the affected browser process.

Critical Impact

This use-after-free vulnerability could enable remote code execution through specially crafted web content, compromising user systems without requiring any privileges or user interaction beyond visiting a malicious webpage.

Affected Products

• Mozilla Firefox versions prior to 146.0.1

Discovery Timeline

• 2025-12-18 - CVE-2025-14860 published to NVD
• 2025-12-30 - Last updated in NVD database

Technical Details for CVE-2025-14860

Vulnerability Analysis

This use-after-free vulnerability resides in Firefox's Disability Access APIs component, which provides accessibility features for users with disabilities. Use-after-free vulnerabilities occur when an application continues to reference memory after it has been freed, leading to undefined behavior that attackers can exploit.

In this case, the vulnerability (tracked as Mozilla Bug Report #2000597) involves improper lifecycle management of accessibility-related objects. When these objects are deallocated but subsequently accessed, attackers can potentially manipulate the freed memory region to achieve code execution.

The attack vector is network-based, meaning exploitation can occur remotely through malicious web content. No authentication or user interaction beyond visiting a compromised webpage is required, making this vulnerability particularly dangerous for drive-by attacks.

Root Cause

The root cause is classified as CWE-416 (Use After Free), indicating improper memory management in the Disability Access APIs component. The vulnerability stems from a failure to properly track object lifetimes, allowing references to persist after the underlying memory has been freed. This creates a dangling pointer condition that can be exploited through memory corruption techniques.

Attack Vector

The vulnerability is exploitable over the network without requiring any privileges or user interaction. An attacker could craft a malicious webpage that triggers the use-after-free condition in the accessibility APIs, potentially gaining arbitrary code execution within the browser sandbox. Successful exploitation could lead to complete compromise of confidentiality, integrity, and availability of the affected system.

The attack does not require the user to have accessibility features explicitly enabled, as the vulnerable component may be instantiated through various browser operations involving the accessibility subsystem.

Detection Methods for CVE-2025-14860

Indicators of Compromise

• Unusual browser crashes or memory corruption errors related to accessibility features
• Suspicious network connections originating from Firefox processes after visiting unknown websites
• Memory access violations in Firefox logs referencing accessibility API components
• Unexpected child processes spawned by Firefox indicating potential code execution

Detection Strategies

• Monitor Firefox version deployments across endpoints to identify installations running versions below 146.0.1
• Implement browser crash telemetry analysis to detect patterns consistent with use-after-free exploitation attempts
• Deploy endpoint detection rules for memory corruption artifacts in browser processes
• Utilize SentinelOne Singularity platform to detect anomalous browser behavior and potential post-exploitation activity

Monitoring Recommendations

• Enable browser telemetry and crash reporting to identify potential exploitation attempts
• Configure security monitoring tools to alert on Firefox versions vulnerable to CVE-2025-14860
• Monitor for unusual memory allocation patterns in browser processes
• Implement web filtering to block known malicious domains that may attempt exploitation

How to Mitigate CVE-2025-14860

Immediate Actions Required

• Update Mozilla Firefox to version 146.0.1 or later immediately
• Enable automatic updates for Firefox to ensure timely application of security patches
• Consider temporarily disabling accessibility features if updates cannot be applied immediately
• Implement network-level protections to filter potentially malicious web content

Patch Information

Mozilla has released Firefox version 146.0.1 to address this vulnerability. The fix is documented in Mozilla Security Advisory MFSA-2025-98. Organizations should prioritize this update given the critical severity and network-based attack vector.

To update Firefox:

1. Open Firefox and navigate to Help > About Firefox
2. Firefox will automatically check for and download updates
3. Click Restart to update Firefox when prompted
4. Verify the version displays 146.0.1 or higher

Workarounds

• Restrict browsing to trusted websites only until the patch can be applied
• Use alternative browsers for untrusted web content until Firefox is updated
• Implement network security controls such as web proxies with content inspection
• Consider disabling JavaScript on untrusted sites to reduce attack surface

# Verify Firefox version from command line
firefox --version

# Enterprise deployment: Force update via policy
# Create or modify policies.json in Firefox installation directory
cat << 'EOF' > /usr/lib/firefox/distribution/policies.json
{
  "policies": {
    "DisableAppUpdate": false,
    "AppAutoUpdate": true
  }
}
EOF