CVE-2024-2615: Mozilla Firefox RCE Vulnerability

CVE-2024-2615 Overview

CVE-2024-2615 is a memory safety vulnerability affecting Mozilla Firefox versions prior to 124. Multiple memory safety bugs were discovered in Firefox 123, with some showing evidence of memory corruption. Mozilla's security team has confirmed that with sufficient effort, these vulnerabilities could potentially be exploited to execute arbitrary code on affected systems. This vulnerability falls under CWE-787 (Out-of-Bounds Write), a dangerous class of memory corruption issues that can lead to complete system compromise.

Critical Impact

Memory corruption vulnerabilities in Firefox 123 could allow attackers to execute arbitrary code remotely, potentially leading to complete browser compromise and unauthorized access to user data.

Affected Products

• Mozilla Firefox versions prior to 124
• Mozilla Firefox 123 and earlier releases

Discovery Timeline

• 2024-03-19 - CVE-2024-2615 published to NVD
• 2025-03-14 - Last updated in NVD database

Technical Details for CVE-2024-2615

Vulnerability Analysis

This vulnerability represents a collection of memory safety bugs discovered in Firefox 123's codebase. Memory safety vulnerabilities of this nature occur when the browser improperly handles memory allocation, deallocation, or access operations. The underlying CWE-787 (Out-of-Bounds Write) classification indicates that the affected code writes data past the boundaries of allocated memory buffers, potentially corrupting adjacent memory regions.

The attack can be initiated remotely over the network without requiring any user privileges or interaction, making it particularly dangerous. When exploited, an attacker could achieve arbitrary code execution with the privileges of the Firefox browser process, potentially gaining access to sensitive user data, session tokens, and the ability to perform actions on behalf of the user.

Root Cause

The root cause stems from improper memory handling within Firefox 123's internal components. Out-of-bounds write vulnerabilities typically arise from insufficient bounds checking when copying data into fixed-size buffers, integer overflow conditions that lead to undersized allocations, or incorrect calculations of memory boundaries. Multiple related bugs (tracked in Mozilla's Bugzilla as bugs 1881074, 1882438, and 1881650) contribute to this vulnerability classification.

Attack Vector

The vulnerability is exploitable via the network attack vector. An attacker could craft malicious web content designed to trigger the memory corruption conditions when processed by a vulnerable Firefox browser. Successful exploitation does not require user authentication or special privileges—simply visiting a malicious webpage or loading attacker-controlled content could trigger the vulnerability.

Exploitation scenarios include:

• Hosting malicious JavaScript or HTML content on attacker-controlled websites
• Injecting exploit code through compromised advertising networks
• Leveraging social engineering to direct users to weaponized pages
• Man-in-the-middle attacks to inject malicious content into HTTP traffic

The memory corruption nature of this vulnerability means that exploits may need to overcome browser security mitigations like ASLR (Address Space Layout Randomization) and DEP (Data Execution Prevention), though skilled attackers have historically bypassed such protections.

Detection Methods for CVE-2024-2615

Indicators of Compromise

• Unexpected Firefox crashes or hangs when browsing specific websites
• Anomalous memory consumption patterns in the Firefox process
• Evidence of child processes spawned by Firefox with unexpected command lines
• Browser-initiated network connections to unknown or suspicious destinations
• Unexpected file system access or modifications originating from the browser process

Detection Strategies

• Monitor Firefox version deployments across the enterprise to identify instances running version 123 or earlier
• Implement browser telemetry analysis to detect abnormal crash patterns potentially indicative of exploitation attempts
• Deploy endpoint detection capabilities that monitor for suspicious process behaviors originating from browser processes
• Utilize network security tools to identify potentially malicious web content targeting browser vulnerabilities

Monitoring Recommendations

• Enable Firefox crash reporting and monitor for patterns that may indicate exploitation attempts
• Configure SIEM rules to alert on unusual browser process behaviors such as unexpected child process creation
• Monitor for network traffic to domains associated with known exploit kits or malware distribution
• Implement browser isolation technologies for high-risk browsing activities

How to Mitigate CVE-2024-2615

Immediate Actions Required

• Update all Firefox installations to version 124 or later immediately
• Enable automatic updates in Firefox to ensure timely deployment of security patches
• Implement browser isolation for users who cannot immediately update
• Consider temporary use of alternative browsers for sensitive activities until patching is complete
• Review and restrict access to untrusted websites where possible

Patch Information

Mozilla has addressed this vulnerability in Firefox version 124. The security fix is documented in Mozilla Security Advisory MFSA-2024-12. Organizations should prioritize updating to Firefox 124 or later to remediate this vulnerability. The advisory provides complete details on the security fixes included in this release.

Technical details about the specific bugs addressed can be found in the Mozilla Bug List Report.

Workarounds

• Deploy browser isolation solutions to contain potential exploitation within sandboxed environments
• Implement strict Content Security Policy (CSP) headers on internal web applications to reduce attack surface
• Use network-level filtering to block access to known malicious domains and untrusted content
• Consider disabling JavaScript execution on untrusted sites through browser extensions or enterprise policies as a temporary measure
• Enable Firefox's Enhanced Tracking Protection in Strict mode for additional defense-in-depth

# Firefox Enterprise Policy Configuration (policies.json)
# Place in Firefox installation directory under /distribution/
{
  "policies": {
    "DisableTelemetry": false,
    "AppAutoUpdate": true,
    "ExtensionUpdate": true,
    "BlockAboutConfig": false,
    "DisableSecurityBypass": {
      "InvalidCertificate": true,
      "SafeBrowsing": true
    }
  }
}