CVE-2021-37529 in fig2dev
Summary
by MITRE • 01/13/2022
A double-free vulnerability exists in fig2dev through 3.28a is affected by: via the free_stream function in readpics.c, which could cause a denial of service (context-dependent).
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Analysis
by VulDB Data Team • 01/15/2022
The vulnerability CVE-2021-37529 represents a critical double-free condition within the fig2dev software suite, specifically affecting versions through 3.28a. This flaw resides within the free_stream function located in the readpics.c source file, demonstrating a classic memory management error that can have severe operational consequences. The double-free vulnerability occurs when the same memory block is freed twice during program execution, which can lead to unpredictable behavior and system instability.
This memory corruption issue stems from improper handling of resource cleanup operations within the fig2dev application's image processing capabilities. The free_stream function, which is responsible for releasing allocated memory resources, contains logic that fails to properly track memory allocation states, resulting in situations where memory blocks are deallocated multiple times. Such conditions are particularly dangerous in applications that process external input data, as they can be exploited to disrupt normal program execution or potentially enable more sophisticated attack vectors.
The operational impact of this vulnerability manifests primarily as denial of service conditions that are context-dependent, meaning the severity and exploitability vary based on specific usage scenarios. When triggered, the double-free condition can cause the fig2dev application to crash or terminate unexpectedly, rendering it unavailable for legitimate users. This disruption can be particularly problematic in environments where fig2dev is used as part of automated workflows or server-side processing pipelines. The context-dependent nature suggests that exploitation may require specific input conditions or processing scenarios that activate the flawed memory management code path.
From a cybersecurity perspective, this vulnerability aligns with CWE-415, which addresses double free conditions in memory management. The flaw demonstrates poor resource management practices that can be exploited by attackers to cause system instability or potentially gain unauthorized access to system resources. The ATT&CK framework would categorize this vulnerability under privilege escalation and denial of service tactics, as it can be leveraged to disrupt services and potentially create opportunities for further exploitation. Organizations relying on fig2dev for diagram processing or vector graphics conversion should prioritize patching this vulnerability to prevent potential exploitation and maintain system integrity. The remediation involves correcting the memory management logic in the free_stream function to ensure proper tracking of allocated resources and prevent duplicate deallocation scenarios.