CVE-2024-47540: GStreamer RCE Vulnerability

CVE-2024-47540 Overview

CVE-2024-47540 is an uninitialized stack variable vulnerability discovered in GStreamer, a widely-used open-source multimedia framework for constructing graphs of media-handling components. The vulnerability exists within the gst_matroska_demux_add_wvpk_header function in matroska-demux.c, where improper handling of buffer operations can lead to function pointer hijacking and potentially arbitrary code execution.

Critical Impact

An attacker can exploit this uninitialized memory vulnerability to hijack execution flow, potentially achieving arbitrary code execution on systems processing malicious media files.

Affected Products

• GStreamer versions prior to 1.24.10
• Linux distributions shipping vulnerable GStreamer packages
• Applications and media players built on the GStreamer framework

Discovery Timeline

• 2024-12-12 - CVE-2024-47540 published to NVD
• 2026-03-17 - Last updated in NVD database

Technical Details for CVE-2024-47540

Vulnerability Analysis

The vulnerability stems from improper initialization of a stack variable used in buffer memory mapping operations. When the gst_matroska_demux_add_wvpk_header function processes input where the size parameter is less than 4, the function proceeds to call gst_buffer_unmap with an uninitialized GstMapInfo structure. This uninitialized map variable is then passed to gst_memory_unmap, which attempts to dereference function pointers within the structure.

The attack can be triggered through a local vector, requiring no privileges or user interaction. If successfully exploited, an attacker gains control over the memory unmap function pointer (mem->allocator->mem_unmap_full or mem->allocator->mem_unmap), enabling redirection of program execution to attacker-controlled code.

Root Cause

The root cause is classified under CWE-457 (Use of Uninitialized Variable) and CWE-908 (Use of Uninitialized Resource). The gst_matroska_demux_add_wvpk_header function contains a code path where the GstMapInfo structure is not properly initialized before being used in the buffer unmapping operation. When size < 4, the normal initialization path is skipped, but the cleanup code still attempts to unmap the buffer using the garbage values present in the uninitialized stack variable.

Attack Vector

Exploitation of this vulnerability requires local access to the target system. An attacker could craft a malicious Matroska (MKV) container file with a specially crafted WavPack audio header that triggers the vulnerable code path. When this file is processed by any application using GStreamer's Matroska demuxer, the uninitialized stack variable is used, potentially allowing the attacker to:

1. Control the values in the uninitialized GstMapInfo structure through heap spraying or stack manipulation techniques
2. Hijack the function pointer used in the memory unmap operation
3. Redirect execution to shellcode or ROP chains for arbitrary code execution

The vulnerability occurs during the demuxing phase of media file processing, making any application that uses GStreamer to parse Matroska files a potential target.

Detection Methods for CVE-2024-47540

Indicators of Compromise

• Unexpected crashes or segmentation faults in GStreamer-based applications when processing media files
• Anomalous memory access patterns in processes using libgstmatroska
• Suspicious Matroska/WebM files with malformed WavPack audio headers
• Core dumps showing crashes in gst_memory_unmap or gst_buffer_unmap functions

Detection Strategies

• Deploy file integrity monitoring on GStreamer library files to detect unauthorized modifications
• Implement application-level sandboxing for media processing workflows to contain potential exploitation
• Monitor for unusual process behavior when media files are being processed, such as unexpected child processes or network connections
• Use memory-safe build flags and runtime protections (ASLR, stack canaries) to increase exploitation difficulty

Monitoring Recommendations

• Enable crash reporting and core dump analysis for GStreamer-based applications in production environments
• Implement logging for media file processing operations, particularly for Matroska container parsing
• Monitor system logs for repeated crashes in media processing services that could indicate exploitation attempts
• Deploy endpoint detection and response (EDR) solutions capable of detecting memory corruption exploitation techniques

How to Mitigate CVE-2024-47540

Immediate Actions Required

• Update GStreamer to version 1.24.10 or later, which contains the security fix
• If immediate patching is not possible, restrict processing of untrusted media files on affected systems
• Apply vendor-provided security patches for your Linux distribution
• Review and audit any custom applications that directly interface with GStreamer's Matroska demuxer

Patch Information

The vulnerability has been fixed in GStreamer version 1.24.10. The official patch is available through the GitLab Merge Request #8057. Additional security information is available in the GStreamer Security Advisory SA-2024-0017 and the GitHub Security Advisory GHSL-2024-197.

Debian users should reference the Debian LTS Announcement for distribution-specific patching guidance.

Workarounds

• Implement input validation to reject media files with suspicious or malformed headers before GStreamer processing
• Run GStreamer-based applications in sandboxed environments with limited privileges using tools like Flatpak, Firejail, or containers
• Disable or remove the Matroska demuxer plugin if WavPack audio support is not required in your deployment
• Apply defense-in-depth measures including Address Space Layout Randomization (ASLR) and stack protection mechanisms

# Verify GStreamer version and update on Debian/Ubuntu systems
gst-inspect-1.0 --version

# Update GStreamer packages
sudo apt update
sudo apt install --only-upgrade gstreamer1.0-plugins-good libgstreamer1.0-0

# Verify the updated version
gst-inspect-1.0 --version