CVE-2025-55644: Heap Use-After-Free in GPAC MP4Box v2.4 DoS Vulnerability

Technical summary

CVE-2025-55644 is a heap use-after-free vulnerability (CWE-416) located in the gf_node_get_tag function within scenegraph/base_scenegraph.c of GPAC MP4Box v2.4. The vulnerability arises from a logic error that permits dereferencing of freed heap memory during scene graph traversal when processing MP4 file structures. This memory safety violation is triggered upon receipt of a malformed MP4 file, leading to application termination or potential instability. The use-after-free condition occurs in the scene graph node tag resolution process, a critical component for parsing hierarchical media structures within MP4 containers.

Business impact

The primary business impact is service disruption through denial of service. Organizations using GPAC MP4Box for automated media processing, transcoding pipelines, or content validation may experience crashes that interrupt workflows. The vulnerability affects availability rather than confidentiality or integrity, making it a business continuity concern rather than a data breach risk. Media companies, streaming platforms, and content management systems relying on MP4Box for server-side processing face potential operational disruption if untrusted files are processed without prior validation.

Affected systems

GPAC MP4Box version 2.4 is explicitly affected. Organizations should verify whether this version is deployed in production environments, particularly in media processing pipelines, automated transcoding services, or content analysis workflows. Check for embedded use of GPAC libraries in custom applications. Earlier and later versions require assessment against vendor advisories to confirm scope; assume potential impact across the v2.x line pending explicit vendor communication clarifying unaffected versions.

Exploitability

Exploitation requires local system access or user interaction to open a malicious MP4 file. The attack vector is local (not network-based), and no special privileges are required to trigger the crash. An attacker must craft a specific MP4 file that violates scene graph structure expectations. The ease of creating such a file is moderate—reverse engineering the exact memory conditions requires some sophistication, but the barrier to causing a denial of service is low once a working payload exists. This is not an in-the-wild exploitation scenario currently, as the vulnerability is not listed on CISA's Known Exploited Vulnerabilities catalog.

Remediation

Upgrade GPAC to a patched version released by the maintainers. Pending patch availability, implement compensating controls: restrict processing of MP4 files from untrusted sources, enforce file validation using external tools prior to MP4Box processing, and run MP4Box instances in isolated environments (containers, VMs) with resource limits to minimize crash impact. Implement input validation at the application layer to reject files with suspicious or non-standard scene graph structures before passing them to MP4Box.

Patch guidance

Consult the official GPAC project repository and security advisories for patched version numbers and release dates. Verify patch availability by checking the GPAC GitHub releases page and any published CVE advisories from the maintainers. Organizations should prioritize testing patches in non-production environments before deployment. If a patch is not yet available, maintain heightened monitoring for release announcements and set up alerts for GPAC security updates.

Detection guidance

Monitor for MP4Box process crashes or unexpected terminations, particularly when correlated with ingestion of new or external media files. Log application errors related to heap memory violations or segmentation faults. Implement file integrity and behavior monitoring for media processing pipelines. Network-based detection is limited due to the local attack vector; focus on endpoint logging and process crash events. File-based detection of malicious MP4 structures requires deep packet inspection or file heuristics tuned to scene graph anomalies—this is best handled by upstream validation before MP4Box processing.

Why prioritize this

This vulnerability merits prompt but measured attention. The CVSS 5.5 (MEDIUM) score reflects the local attack vector and user interaction requirement, which reduce immediate enterprise risk compared to network-exploitable flaws. However, organizations with unattended or user-facing media processing pipelines should prioritize patching sooner, as a DoS condition can directly impact service availability. The lack of KEV status indicates this is not currently being exploited in the wild, reducing time-critical urgency. Prioritize patching if MP4Box processes untrusted files; deprioritize if usage is limited to internal, validated content.

Risk score, explained

The CVSS 3.1 score of 5.5 reflects a Medium severity: attack is local, requires user interaction (opening a file), carries low complexity, and impacts availability only (no confidentiality or integrity loss). The score appropriately captures the operational risk while excluding credential theft, data exfiltration, or privilege escalation scenarios. Organizations with automated, high-throughput media processing may perceive higher business risk than the base score suggests, warranting contextual elevation of priority.

Frequently asked questions