CVE-2024-2614: Mozilla Firefox RCE Vulnerability

CVE-2024-2614 Overview

CVE-2024-2614 is a memory safety vulnerability affecting Mozilla Firefox, Firefox ESR, and Thunderbird. Mozilla developers and community members identified memory safety bugs in Firefox 123, Firefox ESR 115.8, and Thunderbird 115.8. Some of these bugs demonstrated evidence of memory corruption. Mozilla assesses that attackers could have exploited some of these issues to run arbitrary code with sufficient effort. The flaw is tracked under [CWE-787] (Out-of-Bounds Write) and impacts Firefox versions before 124, Firefox ESR before 115.9, and Thunderbird before 115.9. Debian Linux distributions shipping these packages are also affected.

Critical Impact
Memory corruption in Firefox and Thunderbird can lead to arbitrary code execution in the browser or mail client process when a victim loads attacker-controlled content.

Affected Products

Mozilla Firefox versions prior to 124
Mozilla Firefox ESR versions prior to 115.9
Mozilla Thunderbird versions prior to 115.9 and Debian Linux 10 distributions bundling these packages

Discovery Timeline

2024-03-19 - CVE-2024-2614 published to the National Vulnerability Database
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2024-2614

Vulnerability Analysis

CVE-2024-2614 aggregates multiple memory safety defects reported against Firefox 123, Firefox ESR 115.8, and Thunderbird 115.8. Mozilla classifies these bugs under [CWE-787], indicating out-of-bounds write conditions in native browser code. When triggered, memory corruption can overwrite adjacent objects, function pointers, or heap metadata. An attacker who controls the corruption primitive can pivot toward arbitrary code execution in the affected process.

The vulnerability requires network attack vector and low privileges, with no user interaction beyond loading malicious web content or a crafted email message. Referenced bug identifiers include 1685358, 1861016, 1880405, and 1881093 in Mozilla's Bugzilla tracker.

Root Cause

The root cause is improper bounds checking in native C/C++ code paths within the Gecko rendering engine and supporting components shared by Firefox and Thunderbird. These issues result in out-of-bounds writes to memory the process did not intend to modify. Mozilla did not disclose specific per-bug details in the advisory to protect users during the patch rollout.

Attack Vector

Exploitation occurs remotely over the network. An attacker hosts a malicious web page or sends a crafted HTML email that triggers the vulnerable code paths in Firefox or Thunderbird. Successful exploitation could yield code execution within the browser or mail client sandbox. See Mozilla Security Advisory MFSA-2024-12, MFSA-2024-13, and MFSA-2024-14 for vendor detail.

Detection Methods for CVE-2024-2614

Indicators of Compromise

Firefox or Thunderbird process crashes with signatures consistent with heap or stack corruption in the Gecko engine.
Child content processes spawning unexpected child processes such as cmd.exe, powershell.exe, or shell interpreters.
Unexpected outbound network connections from firefox.exe or thunderbird.exe to unknown infrastructure following a page load or email preview.

Detection Strategies

Inventory endpoints running Firefox below version 124, Firefox ESR below 115.9, or Thunderbird below 115.9 using software asset management data.
Monitor process lineage for browser or mail client processes launching command interpreters, script hosts, or LOLBins.
Correlate browser crash telemetry with subsequent process creation events to identify post-exploitation activity.

Monitoring Recommendations

Ingest browser and mail client telemetry into a centralized data lake for behavioral analysis.
Alert on abnormal memory access patterns and crash reports originating from libxul or Gecko modules.
Track patch compliance across Firefox, Firefox ESR, and Thunderbird deployments and flag hosts that remain on vulnerable versions.

How to Mitigate CVE-2024-2614

Immediate Actions Required

Upgrade Firefox to version 124 or later on all managed endpoints.
Upgrade Firefox ESR to version 115.9 or later where extended support release channels are in use.
Upgrade Thunderbird to version 115.9 or later across all mail client installations.
Apply Debian security updates published in Debian LTS Announcement #22 and Debian LTS Announcement #28.

Patch Information

Mozilla released fixes in Firefox 124, Firefox ESR 115.9, and Thunderbird 115.9. Refer to MFSA-2024-12, MFSA-2024-13, and MFSA-2024-14 for the complete list of addressed bugs and download links. Debian-based systems should apply updates through the standard package management channels.

Workarounds

No official workaround exists; patching is the required remediation path.
Restrict browsing to trusted sites and disable HTML rendering in Thunderbird as an interim risk reduction while patches are staged.
Enforce endpoint policies that block browsers and mail clients from spawning script interpreters or shells.

bash

# Debian/Ubuntu patch installation example
sudo apt-get update
sudo apt-get install --only-upgrade firefox-esr thunderbird
firefox --version
thunderbird --version