CVE-2021-40942 in GPAC
Summary
by MITRE • 06/28/2022
In GPAC MP4Box v1.1.0, there is a heap-buffer-overflow in the function filter_parse_dyn_args function in filter_core/filter.c:1454, as demonstrated by GPAC. This can cause a denial of service (DOS).
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Analysis
by VulDB Data Team • 07/16/2022
The vulnerability CVE-2021-40942 represents a critical heap buffer overflow condition within GPAC MP4Box version 1.1.0 that specifically affects the filter_parse_dyn_args function located in the filter_core/filter.c source file at line 1454. This memory corruption flaw arises during the processing of dynamic arguments within the GPAC media processing framework, where insufficient bounds checking allows maliciously crafted input data to overwrite adjacent heap memory regions. The vulnerability stems from improper input validation and memory management practices that fail to adequately verify the size and content of dynamically allocated buffers before writing data to them.
The technical exploitation of this heap buffer overflow occurs when the filter_parse_dyn_args function processes malformed or oversized argument inputs that exceed the allocated buffer boundaries. This condition creates a situation where adjacent memory locations become overwritten with unexpected data patterns, potentially leading to arbitrary code execution or system instability. The vulnerability is particularly concerning because it operates within a core media processing component that handles various multimedia file formats and streaming protocols, making it susceptible to exploitation through crafted media files or network streams. The heap corruption can manifest in unpredictable ways including application crashes, memory corruption, or in worst-case scenarios, potential privilege escalation depending on the execution context.
From an operational perspective, this vulnerability presents a significant denial of service risk to systems utilizing GPAC MP4Box for media processing tasks such as video transcoding, format conversion, or streaming operations. Attackers can trigger the overflow by providing specially crafted input parameters that cause the application to allocate insufficient memory for dynamic argument processing, leading to system instability and potential service interruption. The impact extends beyond simple service disruption as the memory corruption could potentially be leveraged for more sophisticated attacks if the application executes in a privileged context or if the heap layout allows for controlled data overwrite patterns. This vulnerability affects multimedia processing environments including content delivery networks, media servers, and digital asset management systems that rely on GPAC for format conversion and streaming operations.
Mitigation strategies for CVE-2021-40942 should prioritize immediate patch application from GPAC maintainers to address the heap buffer overflow condition through proper bounds checking and memory allocation validation. Organizations should implement input validation controls that sanitize all dynamic argument inputs before processing, employ address space layout randomization techniques, and utilize heap memory protection mechanisms such as stack canaries or heap metadata validation. The vulnerability aligns with CWE-121 heap-based buffer overflow classification and represents a potential entry point for attackers following ATT&CK technique T1059.007 for command and scripting interpreter execution. System administrators should monitor for unusual application behavior, implement intrusion detection systems to identify exploitation attempts, and consider network segmentation to limit potential attack vectors. Regular security assessments and vulnerability scanning should be conducted to identify similar memory corruption issues within the GPAC framework and other multimedia processing libraries that may present similar attack surfaces.