CVE-2020-21530 in fig2dev
Summary
by MITRE • 09/17/2021
fig2dev 3.2.7b contains a segmentation fault in the read_objects function in read.c.
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Analysis
by VulDB Data Team • 09/22/2021
The vulnerability identified as CVE-2020-21530 affects fig2dev version 3.2.7b, a tool used for converting graphic files from one format to another within the GNU FreeForm library ecosystem. This particular flaw manifests as a segmentation fault occurring within the read_objects function located in the read.c source file, representing a critical issue that could potentially disrupt the normal operation of applications relying on this conversion utility. The segmentation fault indicates that the program attempts to access memory locations it should not have access to, leading to an abrupt termination of the process. This vulnerability specifically impacts systems where fig2dev is utilized for processing graphic files, particularly in automated environments where such failures could cascade into broader operational disruptions.
The technical root cause of this vulnerability stems from improper input validation within the read_objects function, which fails to adequately handle malformed or maliciously crafted graphic input files. When the function processes certain file structures, it does not perform sufficient bounds checking or memory access validation before attempting to read or manipulate data structures. This lack of proper boundary validation creates an environment where an attacker could craft a specially formatted graphic file that would trigger the segmentation fault during processing. The vulnerability aligns with CWE-125, which describes out-of-bounds read conditions, and CWE-248, which covers unspecified other runtime errors. The flaw represents a classic example of insufficient input sanitization that allows for memory corruption scenarios.
From an operational standpoint, this segmentation fault vulnerability presents significant risks to systems that depend on fig2dev for graphic file processing, particularly in automated workflows or server environments where continuous operation is critical. The vulnerability could be exploited by attackers to cause denial of service conditions, where legitimate users are unable to process graphic files due to the application crashing. In environments where fig2dev is used as part of larger software pipelines or web applications, this could result in cascading failures affecting multiple downstream processes. The impact extends beyond simple service interruption as it could potentially be leveraged in more sophisticated attacks, especially when combined with other vulnerabilities in the same software ecosystem or when the tool is used in contexts where attackers might have the ability to influence input files. This vulnerability also aligns with ATT&CK technique T1499.004, which covers network denial of service attacks, and T1550.001, which involves use of valid accounts to compromise systems.
Mitigation strategies for CVE-2020-21530 should prioritize immediate software updates to versions that contain patches addressing the segmentation fault issue in the read_objects function. System administrators should implement comprehensive input validation measures for any graphic files processed through fig2dev, including file format verification and size limitations to prevent exploitation attempts. Additionally, deploying intrusion detection systems that monitor for abnormal process termination patterns or memory access violations can help identify exploitation attempts. Organizations should also consider implementing sandboxing mechanisms for graphic file processing to isolate potential exploitation attempts from core system operations. Regular security assessments of the GNU FreeForm library and related tools should be conducted to identify similar vulnerabilities that may exist in the broader ecosystem, as this type of memory corruption flaw often indicates potential for additional related vulnerabilities within the same codebase. The vulnerability highlights the importance of maintaining up-to-date software libraries and implementing robust input validation practices across all components that handle external data processing.