CVE-2018-13847 in Bento4
Summary
by MITRE
An issue has been found in Bento4 1.5.1-624. It is a SEGV in AP4_StcoAtom::AdjustChunkOffsets in Core/Ap4StcoAtom.cpp.
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Analysis
by VulDB Data Team • 04/06/2023
The vulnerability identified as CVE-2018-13847 represents a critical memory corruption issue within the Bento4 multimedia framework version 1.5.1-624. This flaw manifests as a segmentation fault occurring in the AP4_StcoAtom::AdjustChunkOffsets function located within the Core/Ap4StcoAtom.cpp source file. The issue arises from improper handling of chunk offset adjustments in mp4 container structures, specifically affecting the atom structure that manages chunk offsets for media data positioning within mp4 files. The vulnerability demonstrates a classic buffer over-read condition that can lead to application crashes and potentially more severe security implications when processing malformed mp4 files.
The technical root cause of this vulnerability stems from inadequate input validation and boundary checking within the chunk offset adjustment mechanism. When the AP4_StcoAtom::AdjustChunkOffsets function processes media data structures, it fails to properly validate the offsets and chunk information provided in the mp4 atom. This weakness creates an exploitable condition where an attacker can craft malicious mp4 files that trigger memory corruption during the adjustment process. The vulnerability specifically affects the handling of the stco (chunk offset) atom which is fundamental to mp4 file structure organization and media data retrieval. This issue aligns with CWE-129, which addresses improper validation of input boundaries, and CWE-787, concerning out-of-bounds write operations that can lead to memory corruption and system instability.
The operational impact of CVE-2018-13847 extends beyond simple application crashes, potentially enabling more sophisticated attack vectors when exploited in broader contexts. Systems that process or parse mp4 files using the affected Bento4 library become vulnerable to denial of service attacks, where maliciously crafted media files can cause applications to crash repeatedly. In environments where automated media processing occurs, this vulnerability can lead to service disruption and resource exhaustion. The vulnerability's exploitation potential increases when considering that mp4 files are widely used across various platforms including web browsers, media players, and content management systems, making the attack surface substantial. From an ATT&CK perspective, this vulnerability could be leveraged as part of initial access or persistence mechanisms, particularly in scenarios where media files are processed as part of larger attack chains.
Mitigation strategies for CVE-2018-13847 require immediate patching of the Bento4 library to version 1.5.1-625 or later, which contains the necessary fixes for the chunk offset adjustment logic. Organizations should implement strict input validation measures for all mp4 file processing workflows, including preliminary file format checking and size validation before deeper parsing occurs. Network-based defenses can include implementing content filtering systems that scan for suspicious mp4 file characteristics, while endpoint protection solutions should monitor for abnormal application behavior during media file processing. Additional defensive measures involve deploying sandboxing mechanisms for media file handling and establishing robust monitoring protocols to detect potential exploitation attempts. The fix implemented in the patched version addresses the core boundary checking issues in the AP4_StcoAtom::AdjustChunkOffsets function, ensuring that all chunk offset adjustments properly validate input parameters and maintain memory integrity throughout the processing cycle.