CVE-2015-8792 in libMatroska
Summary
by MITRE
The KaxInternalBlock::ReadData function in libMatroska before 1.4.4 allows context-dependent attackers to obtain sensitive information from process heap memory via crafted EBML lacing, which triggers an invalid memory access.
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Analysis
by VulDB Data Team • 11/07/2024
The vulnerability identified as CVE-2015-8792 resides within the libMatroska library version 1.4.4 and earlier, specifically within the KaxInternalBlock::ReadData function. This flaw represents a critical information disclosure issue that arises from improper handling of EBML (Extensible Binary Meta Language) lacing structures during media file parsing operations. The vulnerability manifests when attackers craft malicious EBML lacing sequences that cause the library to access invalid memory regions, potentially exposing sensitive data from the process heap memory. This type of vulnerability falls under the category of information exposure through improper error handling and memory management practices.
The technical exploitation of this vulnerability occurs through a context-dependent attack vector where specifically crafted media files containing malformed EBML lacing can trigger the vulnerable code path. When the KaxInternalBlock::ReadData function processes these malicious inputs, it fails to properly validate the lacing parameters and memory boundaries, leading to memory access violations that inadvertently leak heap memory contents. The underlying issue stems from inadequate bounds checking and memory access validation within the EBML parsing logic, which allows attackers to manipulate the parsing state and extract unintended data from adjacent memory locations. This vulnerability is classified as a CWE-125 vulnerability, representing an out-of-bounds read condition that occurs when the application attempts to read memory beyond the intended buffer boundaries.
From an operational standpoint, this vulnerability presents significant risks to systems that process media files using the affected libMatroska library. Applications that handle video content, particularly those involving streaming services, media players, or content processing pipelines, become vulnerable to information disclosure attacks. The leaked heap memory could contain sensitive information such as user credentials, session tokens, application state data, or other confidential information stored in memory. The impact extends beyond simple data leakage as this vulnerability could potentially aid in more sophisticated attacks by providing attackers with additional information about the target system's memory layout and internal state. Security professionals should note that this vulnerability aligns with ATT&CK technique T1005, which focuses on data from local system collection, and T1068, which involves exploitation of remote services.
Mitigation strategies for CVE-2015-8792 primarily involve upgrading to libMatroska version 1.4.4 or later, where the vulnerability has been addressed through improved memory validation and bounds checking mechanisms. Organizations should implement comprehensive patch management procedures to ensure all systems utilizing the affected library receive updates promptly. Additional defensive measures include implementing strict input validation for media files, deploying sandboxing mechanisms for media processing operations, and monitoring for unusual memory access patterns that could indicate exploitation attempts. Network-based detection methods should focus on identifying malformed media files that attempt to trigger the vulnerable parsing paths, while host-based solutions should monitor for heap memory access violations and unauthorized memory reads. The vulnerability serves as a reminder of the importance of proper memory management in multimedia processing libraries and the critical need for thorough input validation in applications handling binary data formats.