CVE-2021-44342 in ok-file-formats
Summary
by MITRE • 02/28/2022
David Brackeen ok-file-formats 203defd is vulnerable to Buffer Overflow via function ok_png_transform_scanline() in "/ok_png.c:494".
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Analysis
by VulDB Data Team • 03/04/2022
The vulnerability identified as CVE-2021-44342 affects the ok-file-formats library version 203defd and represents a critical buffer overflow condition within the png image processing functionality. This flaw exists in the ok_png_transform_scanline() function located at line 494 of the ok_png.c source file, making it a significant security concern for any application that processes png images through this library. The buffer overflow occurs when the function processes scanline data during png transformation operations, creating potential for arbitrary code execution or system compromise.
The technical nature of this vulnerability stems from improper bounds checking during memory allocation and data processing within the png decoding pipeline. When the ok_png_transform_scanline() function handles incoming scanline data, it fails to adequately validate the size of input data against allocated buffer boundaries. This condition allows an attacker to provide maliciously crafted png files that can overwrite adjacent memory locations, potentially leading to stack corruption, heap corruption, or controlled memory overwrite scenarios. The vulnerability directly maps to CWE-121, which describes stack-based buffer overflow conditions, and CWE-122, which covers heap-based buffer overflow scenarios that can occur during dynamic memory allocation.
From an operational perspective, this vulnerability presents substantial risk to applications that utilize the ok-file-formats library for image processing, particularly those handling untrusted user uploads or third-party png files. The impact extends beyond simple denial of service to potentially enable remote code execution, privilege escalation, or data corruption within affected systems. Attackers could exploit this vulnerability by crafting specially formatted png files that trigger the buffer overflow condition when processed by applications using the vulnerable library. This makes the vulnerability particularly dangerous in web applications, content management systems, or any platform that accepts png image uploads from untrusted sources.
The attack surface for this vulnerability is broad given the widespread use of png image formats and the prevalence of the ok-file-formats library in various applications. Systems that process png images without proper input validation become vulnerable to exploitation, especially when these applications run with elevated privileges or handle sensitive data. The vulnerability's classification under the ATT&CK framework would fall under T1059.007 for command and scripting interpreter and potentially T1566 for malicious file execution, as exploitation could lead to arbitrary code execution. Organizations should prioritize immediate remediation through library updates, input validation implementation, or alternative image processing libraries to prevent exploitation of this buffer overflow condition.
Mitigation strategies should include immediate patching of the affected library version to the latest secure release, implementation of strict input validation for all png file processing, and deployment of web application firewalls or content filtering systems that can detect and block suspicious png file patterns. Additionally, applications should employ memory safety techniques such as stack canaries, address space layout randomization, and heap metadata protection to reduce exploitability. Regular security assessments and vulnerability scanning should be conducted to identify any other potential buffer overflow conditions within the application's image processing pipeline, ensuring comprehensive protection against similar vulnerabilities that could arise from improper memory management in multimedia processing libraries.