CVE-2020-23928 in GPAC
Summary
by MITRE • 04/22/2021
An issue was discovered in gpac before 1.0.1. The abst_box_read function in box_code_adobe.c has a heap-based buffer over-read.
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Analysis
by VulDB Data Team • 04/28/2021
The vulnerability identified as CVE-2020-23928 represents a critical heap-based buffer over-read flaw within the gpac multimedia framework version 1.0.1 and earlier. This issue resides in the abst_box_read function located within the box_code_adobe.c source file, which is part of the broader gpac library responsible for handling multimedia file formats and protocols. The vulnerability manifests when processing specific Adobe-specific box structures within multimedia containers, particularly affecting the parsing of Adobe-specific metadata within mp4 and other related multimedia formats.
The technical flaw stems from inadequate bounds checking within the abst_box_read function, where the code fails to properly validate the size of data being read from the input buffer before attempting to access memory locations beyond the allocated buffer boundaries. This over-read condition occurs when the function processes Adobe-specific box structures without sufficient validation of the data length parameters, allowing an attacker to craft malicious multimedia files that trigger memory access violations. The heap-based nature of this vulnerability means that the over-read occurs within dynamically allocated memory regions, potentially leading to information disclosure, application crashes, or in some scenarios, remote code execution depending on memory layout and exploitation conditions.
The operational impact of this vulnerability extends across numerous applications and systems that rely on gpac for multimedia processing, including media players, streaming servers, content management systems, and digital asset management platforms. Attackers can exploit this flaw by constructing specially crafted multimedia files containing malformed Adobe box structures that trigger the buffer over-read during normal playback or processing operations. The vulnerability is particularly concerning in server-side applications where multimedia files are processed or converted, as it could enable denial of service attacks or potentially provide a foothold for more sophisticated exploitation attempts. This weakness affects the core multimedia processing capabilities of gpac, making it a significant concern for any system handling multimedia content that utilizes this library.
Mitigation strategies for CVE-2020-23928 should prioritize immediate patching of affected gpac versions to 1.0.1 or later, where the buffer over-read issue has been addressed through proper bounds checking implementation. Organizations should also implement input validation measures that restrict the processing of multimedia files from untrusted sources, particularly when these files are being converted or transcoded. Network-based mitigations could include content filtering at ingress points to prevent malicious multimedia files from entering the processing pipeline, while application-level defenses should enforce strict memory access controls and implement proper error handling for buffer operations. This vulnerability aligns with CWE-125, which specifically addresses out-of-bounds read conditions, and may map to ATT&CK technique T1059 for command and control communications if exploited in a remote execution scenario. System administrators should monitor for exploitation attempts through log analysis and implement robust intrusion detection systems to identify potential attacks leveraging this buffer over-read condition.