CVE-2022-31748: Mozilla Firefox RCE Vulnerability

CVE-2022-31748 Overview

CVE-2022-31748 is a memory safety vulnerability affecting Mozilla Firefox versions prior to 101. Mozilla developers Gabriele Svelto, Timothy Nikkel, Randell Jesup, Jon Coppeard, and the Mozilla Fuzzing Team identified multiple memory safety bugs in Firefox 100 that showed evidence of memory corruption. With sufficient effort, these vulnerabilities could potentially be exploited to achieve arbitrary code execution, allowing attackers to run malicious code within the context of the browser.

Critical Impact

Memory corruption vulnerabilities in Firefox 100 could allow remote attackers to execute arbitrary code by exploiting these memory safety issues, potentially leading to complete system compromise.

Affected Products

• Mozilla Firefox versions prior to 101
• Mozilla Firefox 100 and earlier releases

Discovery Timeline

• 2022-12-22 - CVE-2022-31748 published to NVD
• 2025-04-15 - Last updated in NVD database

Technical Details for CVE-2022-31748

Vulnerability Analysis

This vulnerability encompasses multiple memory safety bugs identified through internal security research and fuzzing efforts by Mozilla's development and security teams. The underlying issues represent classic memory corruption patterns that can occur in complex C/C++ codebases like Firefox's Gecko engine. Memory safety vulnerabilities of this nature typically arise from improper memory management, boundary condition violations, or use-after-free scenarios within the browser's rendering or JavaScript execution components.

The vulnerability is classified under CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer), indicating that the core issues relate to buffer boundary operations. These types of vulnerabilities can lead to memory corruption, crashes, and in the worst case, allow attackers to gain control of program execution flow.

Root Cause

The root cause stems from multiple memory safety issues within Firefox 100's codebase. These bugs involve improper memory handling operations that fail to properly validate or restrict memory access within allocated buffer boundaries. The Mozilla Fuzzing Team's systematic testing approach uncovered these issues across various browser components, suggesting the vulnerabilities may span multiple subsystems including rendering, JavaScript processing, and DOM manipulation.

Attack Vector

The attack vector for CVE-2022-31748 is network-based, requiring no user authentication or interaction beyond visiting a malicious webpage. An attacker could craft specially designed web content that triggers the memory corruption conditions. When a victim visits a page containing the exploit payload, the memory safety bugs could be leveraged to corrupt memory in a controlled manner, potentially achieving arbitrary code execution within the browser process. This could allow attackers to install malware, steal sensitive data, or pivot to further attacks on the user's system.

The vulnerability is exploitable remotely through malicious web content, making drive-by download attacks or compromised legitimate websites potential attack scenarios.

Detection Methods for CVE-2022-31748

Indicators of Compromise

• Unusual browser crashes or instability when visiting untrusted websites
• Unexpected child processes spawned by Firefox
• Memory-related error logs in Firefox crash reports
• Anomalous network connections initiated by the browser process

Detection Strategies

• Monitor for Firefox versions below 101 in enterprise asset inventories
• Implement browser version compliance checks across managed endpoints
• Deploy endpoint detection rules for suspicious memory allocation patterns in browser processes
• Analyze crash dump data for signs of memory corruption exploitation attempts

Monitoring Recommendations

• Enable enhanced crash reporting to capture potential exploitation attempts
• Monitor browser process behavior for anomalous activities such as unexpected file system or registry access
• Implement network monitoring for connections to known malicious infrastructure following browser exploitation
• Review Firefox crash statistics for patterns indicating targeted exploitation

How to Mitigate CVE-2022-31748

Immediate Actions Required

• Update Mozilla Firefox to version 101 or later immediately
• Enable automatic updates in Firefox to ensure timely security patches
• Consider using enterprise browser management to enforce minimum version requirements
• Audit all systems for vulnerable Firefox installations

Patch Information

Mozilla addressed these memory safety vulnerabilities in Firefox version 101. The official security advisory MFSA 2022-20 provides details about this and other security fixes included in the release. Organizations should prioritize this update given the critical severity rating and the potential for arbitrary code execution.

Detailed bug reports are available through Mozilla's Bugzilla tracking system.

Workarounds

• Restrict browsing to trusted websites until patching is complete
• Implement content filtering at the network perimeter to block known malicious domains
• Consider using browser isolation technologies for high-risk browsing activities
• Enable Firefox's Enhanced Tracking Protection and security features as additional defense layers

# Check Firefox version on Linux/macOS
firefox --version

# Force update check via command line (if auto-update is available)
# Users should update through Firefox's built-in update mechanism:
# Help > About Firefox > Check for Updates