CVE-2025-55667 in MP4Box
Summary
by MITRE • 10/19/2026
A segmentation violation in the dump_isom_saps function (/mp4box/filedump.c) of GPAC MP4Box v2.5-DEV-rev1672-gc9a31d0e1-masterallows attackers to cause a Denial of Service (DoS) via supplying a crafted MP4 file.
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Analysis
by VulDB Data Team • 10/19/2026
The vulnerability identified in the GPAC MP4Box utility, specifically within the dump_isom_saps function located in the source file /mp4box/filedump.c, represents a critical memory safety issue that can be exploited to disrupt service availability. This flaw is characterized as a segmentation violation, which typically occurs when software attempts to access memory locations that it does not have permission to access or accesses them in an unauthorized manner. In this specific context, the vulnerability arises during the processing of MP4 container files, where the application fails to adequately validate input data before performing pointer arithmetic or array indexing operations. The version affected is GPAC MP4Box v2.5-DEV-rev1672-gc9a31d0e1-master, indicating that this issue exists in development builds and potentially carries over into subsequent releases if not patched.
From a technical perspective, the root cause of this segmentation fault lies in improper bounds checking or null pointer dereferencing within the SAP (Sync Access Point) table parsing logic. When an attacker supplies a crafted MP4 file containing malformed metadata or corrupted structural elements related to sync access points, the dump_isom_saps function may attempt to read from invalid memory addresses. This could result from reading past the end of an allocated buffer due to incorrect length calculations derived from untrusted input data. Such errors are common in C-based multimedia processing tools where performance optimization often leads developers to skip rigorous validation steps under the assumption that inputs will be well-formed, a dangerous assumption when dealing with potentially malicious files received from external sources or generated by automated fuzzing tools.
The operational impact of this vulnerability is primarily focused on Denial of Service conditions for users and systems relying on GPAC MP4Box for media processing tasks. Since segmentation violations typically cause the application to crash immediately upon execution, an attacker can trigger a system halt simply by providing a specially constructed file through any interface that accepts user-uploaded or processed media files. This could affect video editing workflows, streaming server preprocessing pipelines, or automated content analysis systems where MP4Box is used as a backend tool for inspection or conversion. The crash prevents legitimate users from accessing the service and may require manual intervention to restart affected processes, leading to downtime and potential data loss if unsaved work was in progress during the processing of the malicious file.
This vulnerability aligns with CWE-125, Out-of-bounds Read, as it involves reading memory beyond allocated boundaries due to insufficient validation of input dimensions or offsets. Additionally, from a threat modeling perspective using the MITRE ATT&CK framework, this exploit technique falls under Tactic TA0004: Privilege Escalation if the crash leads to state corruption that could be leveraged further, but more directly it maps to Execution techniques involving command injection via crafted files or simply Availability impact through resource exhaustion. However, given the nature of a segmentation fault leading to immediate termination rather than code execution, it is most accurately categorized under Denial of Service vectors where an attacker disrupts service availability by triggering application crashes without gaining persistent access or control over the underlying system.
Mitigation strategies for this vulnerability involve both immediate patching and long-term defensive coding practices. The primary remediation step is to update GPAC MP4Box to a version that includes fixes for memory safety issues in file parsing functions, ensuring that all input data structures are validated against expected bounds before access. Developers should implement strict validation checks within the dump_isom_saps function to verify array indices and buffer lengths prior to dereferencing pointers. Utilizing static analysis tools during development can help identify such out-of-bounds accesses early in the lifecycle. Furthermore, deploying runtime protection mechanisms like Address Sanitizer (ASan) or Data Execution Prevention (DEP) alongside stack canaries can provide additional layers of defense by detecting and terminating unsafe memory operations before they cause catastrophic failures. For end-users, restricting the use of MP4Box to process only trusted files from verified sources reduces exposure to crafted malicious inputs designed specifically to trigger these parsing errors.