CVE-2025-70307: GPAC v2.4.0 Stack Overflow DoS Vulnerability

CVE-2025-70307 Overview

A stack overflow vulnerability has been identified in the dump_ttxt_sample function of GPAC v2.4.0. This vulnerability allows remote attackers to cause a Denial of Service (DoS) condition by sending specially crafted packets to the affected component. GPAC is an open-source multimedia framework used for creating, packaging, and streaming multimedia content.

Critical Impact

Remote attackers can crash GPAC applications by exploiting this stack overflow, leading to service disruption without requiring authentication.

Affected Products

• GPAC v2.4.0
• Applications utilizing the GPAC multimedia framework v2.4.0
• Systems processing untrusted media files with vulnerable GPAC versions

Discovery Timeline

• 2026-01-15 - CVE CVE-2025-70307 published to NVD
• 2026-01-16 - Last updated in NVD database

Technical Details for CVE-2025-70307

Vulnerability Analysis

This vulnerability is classified as CWE-121 (Stack-based Buffer Overflow). The flaw resides in the dump_ttxt_sample function within GPAC's multimedia processing code. When processing specially crafted media packets, the function fails to properly validate input boundaries, leading to a stack overflow condition.

The vulnerability can be exploited remotely over the network without requiring user interaction or prior authentication. While the vulnerability does not allow for data exfiltration or integrity compromise, it can result in complete service disruption by crashing the affected application.

Root Cause

The root cause of this vulnerability is improper bounds checking in the dump_ttxt_sample function when handling timed text (TX3G) samples. The function processes text track data without adequately validating the size of incoming data against the available stack buffer space. When an attacker provides a malformed packet with oversized or malformed text sample data, the function writes beyond the allocated stack buffer boundaries, corrupting the stack and causing the application to crash.

Attack Vector

The attack vector is network-based, meaning an attacker can exploit this vulnerability remotely by sending a crafted media file or packet to a GPAC-based application. The attack does not require any form of authentication or user privileges, making it particularly accessible to potential attackers. The exploitation process involves:

1. Crafting a malicious media file containing a manipulated TX3G (timed text) sample
2. Delivering the malicious file to a target system running GPAC v2.4.0
3. When GPAC processes the file and invokes dump_ttxt_sample, the stack overflow triggers
4. The application crashes, resulting in denial of service

Technical details and proof-of-concept information are available in the GitHub PoC Repository.

Detection Methods for CVE-2025-70307

Indicators of Compromise

• Unexpected crashes or segmentation faults in GPAC-based applications during media file processing
• Application logs showing errors related to the dump_ttxt_sample function or TX3G box processing
• Core dumps indicating stack corruption originating from GPAC multimedia handling routines
• Repeated service restarts of media processing applications without clear cause

Detection Strategies

• Monitor GPAC application logs for stack overflow errors or abnormal termination events
• Implement file integrity monitoring for media files being processed by GPAC applications
• Deploy intrusion detection rules to identify malformed TX3G/timed text media containers
• Use application crash monitoring to detect repeated DoS attempts against media processing services

Monitoring Recommendations

• Enable verbose logging for GPAC applications to capture detailed error information during crashes
• Configure automated alerting for application crashes or unexpected restarts in media processing pipelines
• Monitor network traffic for unusual patterns of media file submissions that could indicate exploitation attempts
• Implement resource monitoring to detect abnormal memory or CPU usage patterns preceding crashes

How to Mitigate CVE-2025-70307

Immediate Actions Required

• Upgrade GPAC to a patched version when available from the GPAC project
• Restrict network access to GPAC-based applications to trusted sources only
• Implement input validation and file scanning for media files before processing with GPAC
• Consider deploying application sandboxing to limit the impact of potential crashes

Patch Information

At the time of publication, users should monitor the official GPAC project repository and security advisories for patch releases addressing this stack overflow vulnerability. The vulnerability was documented with a proof-of-concept available in the GPAC TX3G PoC documentation.

Workarounds

• Disable or avoid using the timed text (TX3G) sample dumping functionality if not required for your use case
• Process untrusted media files in isolated environments or containers to limit DoS impact
• Implement rate limiting on media file processing to reduce the impact of repeated exploitation attempts
• Use network segmentation to protect critical GPAC deployments from untrusted network traffic

# Example: Run GPAC in a restricted environment
# Using ulimit to limit stack size and prevent runaway crashes
ulimit -s 8192
gpac -logs all@info your_media_file.mp4

# Alternative: Run in container with resource limits
docker run --memory=512m --cpus=1 gpac/gpac:latest your_command