CVE-2024-10463 Overview
CVE-2024-10463 is a cross-origin information disclosure vulnerability in Mozilla Firefox and Thunderbird. Video frames could leak between origins under specific conditions, breaking the same-origin policy that isolates web content. The flaw is classified under [CWE-203] (Observable Discrepancy) and affects the browser's video pipeline handling.
Affected releases include Firefox versions before 132, Firefox ESR before 128.4, Firefox ESR before 115.17, Thunderbird before 128.4, and Thunderbird before 132. Mozilla addressed the issue through advisories MFSA-2024-55 through MFSA-2024-59.
Critical Impact
An attacker-controlled page can access video frame data belonging to a different origin, exposing potentially sensitive visual content rendered from a victim's authenticated session.
Affected Products
- Mozilla Firefox versions prior to 132
- Mozilla Firefox ESR versions prior to 128.4 and prior to 115.17
- Mozilla Thunderbird versions prior to 128.4 and prior to 132
Discovery Timeline
- 2024-10-29 - CVE-2024-10463 published to NVD
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2024-10463
Vulnerability Analysis
The vulnerability breaks the browser's same-origin policy for video content. Under specific conditions, video frames rendered from one origin become observable to script running under a different origin. This defeats the isolation guarantees browsers apply to media resources, which are normally treated as opaque when loaded cross-origin without explicit CORS consent.
The issue is tracked in Mozilla Bug Report #1920800. Successful exploitation requires user interaction, typically visiting a malicious page while authenticated to a target site that streams or embeds video content.
Root Cause
The root cause is an observable discrepancy [CWE-203] in the video decoding or compositing path. Frame buffers associated with cross-origin video sources were not consistently isolated from other renderer contexts. As a result, pixel data could be sampled or copied into an origin that should not have access to it, effectively bypassing the tainted canvas protections that normally guard cross-origin media.
Attack Vector
An attacker hosts a malicious web page that embeds or references cross-origin video content. When a victim visits the page, the attacker's script accesses frame data from the cross-origin video source. This can reveal authenticated content such as video calls, personalized media, or otherwise gated visual data. The attack requires no privileges and executes over the network, but does require the victim to load the attacker's page.
No public proof-of-concept code is available for this issue. Technical detail is limited to the Mozilla advisories and the internal bug tracker, which remains access-restricted at the time of writing.
Detection Methods for CVE-2024-10463
Indicators of Compromise
- Firefox or Thunderbird processes reporting version strings below 132 (or ESR below 128.4 / 115.17) in endpoint inventory data.
- Outbound web traffic to unfamiliar domains that embed <video> elements sourcing content from authenticated third-party origins.
- Browser telemetry showing repeated drawImage or captureStream calls against cross-origin video elements from untrusted pages.
Detection Strategies
- Inventory installed browser and mail client versions across the fleet and flag hosts still running vulnerable Firefox or Thunderbird builds.
- Correlate web proxy logs with threat intelligence to identify visits to suspicious pages that embed cross-origin media alongside scripts calling canvas or WebCodecs APIs.
- Monitor for exploitation attempts that combine social engineering lures with video-heavy landing pages, which is the plausible delivery pattern given the user-interaction requirement.
Monitoring Recommendations
- Track patch compliance for Mozilla products using endpoint management data and alert when hosts remain on vulnerable versions after a defined SLA.
- Ingest browser telemetry and proxy logs into a centralized analytics platform to hunt for anomalous cross-origin media access patterns.
- Review the Debian LTS Announcement October 2024 and Debian LTS Announcement November 2024 for distribution-specific package versions to include in vulnerability scans.
How to Mitigate CVE-2024-10463
Immediate Actions Required
- Upgrade Firefox to version 132 or later on all managed endpoints.
- Upgrade Firefox ESR to 128.4 or 115.17 depending on the deployed branch.
- Upgrade Thunderbird to version 128.4 or 132 or later on all mail clients.
- Push updated packages through enterprise software distribution or the operating system package manager without delay.
Patch Information
Mozilla published fixes in the October 2024 release cycle. Refer to Mozilla Security Advisory MFSA-2024-55, MFSA-2024-56, MFSA-2024-57, MFSA-2024-58, and MFSA-2024-59 for full advisory details. Debian users should apply updates described in the Debian LTS Announcement October 2024 and Debian LTS Announcement November 2024.
Workarounds
- Restrict user browsing to trusted sites through enterprise web filtering until patching completes.
- Disable autoplay and reduce use of cross-origin embedded video on internal applications that host sensitive video content.
- Enforce strict Cross-Origin-Resource-Policy and Cross-Origin-Embedder-Policy headers on internal video services to reduce cross-origin exposure.
# Configuration example: enforce upgrade via enterprise policy on Linux
# Debian/Ubuntu
sudo apt-get update && sudo apt-get install --only-upgrade firefox-esr thunderbird
# Verify installed version meets the fixed release
firefox --version
thunderbird --version
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.