CVE-2021-44927 in GPAC
Summary
by MITRE • 12/22/2021
A null pointer dereference vulnerability exists in gpac 1.1.0 in the gf_sg_vrml_mf_append function, which causes a segmentation fault and application crash.
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Analysis
by VulDB Data Team • 12/25/2021
The null pointer dereference vulnerability identified as CVE-2021-44927 represents a critical security flaw within the gpac multimedia framework version 1.1.0. This vulnerability specifically manifests within the gf_sg_vrml_mf_append function, which is responsible for managing VRML (Virtual Reality Modeling Language) multimedia content processing. The issue arises when the application attempts to dereference a null pointer during the execution of multimedia content manipulation operations, leading to an immediate segmentation fault that terminates the application process. This type of vulnerability falls under CWE-476 which specifically addresses null pointer dereference conditions, making it a fundamental memory safety issue that can severely impact the stability and reliability of multimedia applications relying on gpac for content processing.
The technical exploitation of this vulnerability occurs when maliciously crafted VRML content is processed by the affected gpac library, triggering the gf_sg_vrml_mf_append function to attempt accessing memory through a null pointer reference. This flaw creates an execution path where the application fails to properly validate pointer states before dereferencing them, resulting in an immediate crash that prevents normal application operation. The segmentation fault generated by this vulnerability can be leveraged by attackers to perform denial-of-service attacks against systems running applications that utilize gpac for multimedia processing, effectively rendering those systems unusable until the application is manually restarted or the underlying vulnerability is patched.
From an operational perspective, this vulnerability poses significant risks to multimedia applications and content delivery systems that depend on gpac for processing VRML and related multimedia formats. The impact extends beyond simple application crashes to potentially disrupt entire multimedia workflows in content management systems, streaming platforms, and multimedia authoring tools. The vulnerability can be particularly dangerous in server environments where continuous operation is critical, as a single maliciously crafted multimedia file could cause system-wide service disruptions. According to ATT&CK framework category T1499, this vulnerability represents a denial-of-service attack vector that can be exploited to compromise system availability and reliability.
The mitigation strategy for CVE-2021-44927 requires immediate patching of gpac library installations to version 1.1.1 or later, which contains the necessary code modifications to properly validate pointer states before dereferencing. Organizations should implement comprehensive vulnerability management processes to identify all systems running affected gpac versions and prioritize patch deployment according to risk assessment. Additionally, input validation measures should be strengthened to prevent processing of untrusted VRML content, and application sandboxing techniques should be employed to isolate multimedia processing operations. Security monitoring should be enhanced to detect potential exploitation attempts through abnormal application crash patterns or memory access violations. The remediation approach aligns with industry best practices for memory safety vulnerabilities and follows the principle of least privilege by ensuring that multimedia content processing operations are properly validated and secured against null pointer dereference conditions.