CVE-2018-4022 in MKVINFO
Summary
by MITRE
A use-after-free vulnerability exists in the way MKVToolNix MKVINFO v25.0.0 handles the MKV (matroska) file format. A specially crafted MKV file can cause arbitrary code execution in the context of the current user.
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Analysis
by VulDB Data Team • 06/03/2023
The vulnerability CVE-2018-4022 represents a critical use-after-free flaw in MKVToolNix MKVINFO version 25.0.0 that specifically targets the handling of matroska file format structures. This vulnerability exists within the parsing mechanism of MKV files, where the software fails to properly validate memory allocation and deallocation sequences during file processing. The flaw manifests when the application encounters specially crafted malicious MKV files that trigger improper memory management behaviors, leading to potential arbitrary code execution.
The technical implementation of this vulnerability stems from improper memory handling within the MKVINFO tool's parser component. When processing malformed MKV files, the application allocates memory for certain data structures but fails to properly manage the lifecycle of these allocations. Specifically, the vulnerability occurs when the tool attempts to access memory locations that have already been freed, creating a use-after-free condition that can be exploited by attackers. This type of vulnerability is classified under CWE-416 as "Use After Free" and represents a classic memory safety issue that has been prevalent in multimedia processing applications due to complex parsing requirements.
The operational impact of CVE-2018-4022 is significant as it allows remote code execution with the privileges of the current user account. Attackers can craft malicious MKV files that, when opened by an unsuspecting user with MKVToolNix installed, will trigger the vulnerability and execute arbitrary code on the victim's system. This presents a substantial risk in environments where users may encounter untrusted multimedia content, particularly in email attachments or file sharing scenarios. The vulnerability essentially transforms a legitimate media processing tool into a potential attack vector, making it particularly dangerous for users who frequently work with multimedia files.
Mitigation strategies for this vulnerability should focus on immediate software updates to patched versions of MKVToolNix, as the official maintainers have released fixes addressing the memory management issues. Users should also implement defensive measures such as avoiding opening untrusted MKV files, implementing strict file validation procedures, and maintaining updated antivirus signatures that can detect malicious MKV files. From a security operations perspective, this vulnerability aligns with ATT&CK technique T1203 "Exploitation for Client Execution" and highlights the importance of input validation and memory safety practices in multimedia processing applications. Organizations should also consider implementing application whitelisting policies and network-based controls to prevent execution of malicious MKV files in enterprise environments.