CVE-2019-20163 in GPAC
Summary
by MITRE
An issue was discovered in GPAC version 0.8.0 and 0.9.0-development-20191109. There is a NULL pointer dereference in the function gf_odf_avc_cfg_write_bs() in odf/descriptors.c.
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Analysis
by VulDB Data Team • 03/18/2024
The vulnerability identified as CVE-2019-20163 represents a critical null pointer dereference flaw within the GPAC media processing library version 0.8.0 and the development version 0.9.0-20191109. This issue specifically manifests within the gf_odf_avc_cfg_write_bs() function located in the odf/descriptors.c source file, where the software fails to properly validate pointer references before attempting to dereference them. The flaw occurs during the processing of AVC (Advanced Video Coding) configuration data within the Object Descriptor Framework implementation, making it particularly dangerous in multimedia applications that rely on proper descriptor handling.
The technical implementation of this vulnerability stems from insufficient input validation within the AVC configuration writing function, which is part of the broader Object Descriptor Framework used for handling multimedia object descriptors in GPAC. When the function processes malformed or specially crafted input data, it attempts to access a pointer that has not been properly initialized or validated, leading to a null pointer dereference condition. This type of vulnerability falls under CWE-476 which specifically addresses NULL pointer dereference issues in software implementations, and represents a classic example of improper input validation that can be exploited by attackers to cause application crashes or potentially more severe consequences.
The operational impact of this vulnerability extends beyond simple application crashes, as it can be leveraged in various attack scenarios including denial of service attacks against systems that utilize GPAC for media processing. When exploited, the null pointer dereference causes the application to terminate abruptly, potentially disrupting media streaming services, video processing pipelines, or any system that depends on GPAC for handling multimedia content. The vulnerability is particularly concerning in server environments where continuous operation is critical, as it can be used to repeatedly crash services and render them unavailable to legitimate users. This aligns with ATT&CK technique T1499.004 which covers network denial of service attacks through application-level disruptions.
Mitigation strategies for this vulnerability should focus on immediate patching of affected GPAC versions to the latest stable releases that contain the necessary fixes for the null pointer dereference issue. Organizations should also implement input validation measures that can detect and reject malformed media descriptors before they reach the vulnerable function, and consider deploying intrusion detection systems that can identify exploitation attempts targeting this specific flaw. Additionally, application sandboxing and memory protection mechanisms can provide additional layers of defense, while regular security assessments of multimedia processing pipelines should be conducted to identify similar vulnerabilities in related components. The fix typically involves adding proper null pointer checks before dereferencing any pointers within the affected function, ensuring that all input parameters are validated before processing.