CVE-2019-7699 in Bento4
Summary
by MITRE
A heap-based buffer over-read occurs in AP4_BitStream::WriteBytes in Codecs/Ap4BitStream.cpp in Bento4 v1.5.1-627. Remote attackers could leverage this vulnerability to cause an exception via crafted mp4 input, which leads to a denial of service.
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Analysis
by VulDB Data Team • 07/09/2023
The vulnerability identified as CVE-2019-7699 represents a critical heap-based buffer over-read condition within the Bento4 media processing library version 1.5.1-627. This flaw exists in the AP4_BitStream::WriteBytes function located in the Codecs/Ap4BitStream.cpp source file, making it a significant security concern for systems that process mp4 media files. The vulnerability stems from inadequate input validation and memory boundary checking during the bit stream processing operations that are fundamental to mp4 file handling and manipulation.
The technical implementation of this vulnerability allows remote attackers to craft malicious mp4 input files that trigger the buffer over-read condition when the affected library processes these files. When the AP4_BitStream::WriteBytes function attempts to write data to memory locations beyond the allocated buffer boundaries, it results in accessing invalid memory regions. This memory access violation manifests as an exception that terminates the application process, effectively creating a denial of service condition. The heap-based nature of the over-read indicates that the vulnerable memory allocation occurs on the heap rather than the stack, making the exploitation more complex but equally dangerous.
From an operational perspective, this vulnerability poses substantial risks to media processing servers, content delivery networks, and any systems that rely on Bento4 for mp4 file handling and manipulation. The remote exploitation capability means that attackers can potentially disrupt services without requiring local access or physical presence. The denial of service impact can be severe for streaming platforms, media servers, and content management systems that depend on reliable processing of mp4 files. Organizations using vulnerable versions of Bento4 may experience service interruptions, increased resource consumption, and potential data integrity issues when processing maliciously crafted media files.
The vulnerability aligns with CWE-125, which describes "Out-of-bounds Read" conditions where programs access memory locations beyond the boundaries of allocated buffers. This classification indicates that the flaw represents a fundamental memory safety issue that could be exploited to gain unauthorized access to system resources or potentially escalate privileges. The ATT&CK framework categorizes this type of vulnerability under the T1203 technique for "Exploitation for Execution" where attackers leverage memory corruption vulnerabilities to cause system instability or execute malicious code. Organizations should implement immediate mitigation strategies including updating to patched versions of Bento4, implementing input validation controls, and deploying network segmentation to limit the attack surface. Additionally, monitoring systems should be configured to detect unusual patterns in media file processing that could indicate exploitation attempts. The remediation process should include comprehensive testing of updated libraries in controlled environments before deployment to production systems to ensure compatibility and prevent unintended side effects.