CVE-2021-32142 in LibRaw
Summary
by MITRE • 02/17/2023
Buffer Overflow vulnerability in LibRaw linux/unix v0.20.0 allows attacker to escalate privileges via the LibRaw_buffer_datastream::gets(char*, int) in /src/libraw/src/libraw_datastream.cpp.
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Analysis
by VulDB Data Team • 12/30/2025
The buffer overflow vulnerability identified as CVE-2021-32142 affects LibRaw version 0.20.0 on linux/unix systems, representing a critical security flaw that can be exploited to escalate privileges. This vulnerability resides within the LibRaw_buffer_datastream::gets(char*, int) function located in the /src/libraw/src/libraw_datastream.cpp source file, making it a direct target for attackers seeking to leverage memory corruption techniques. The flaw stems from inadequate bounds checking during string operations, creating opportunities for malicious actors to overwrite adjacent memory locations and potentially execute arbitrary code with elevated privileges.
The technical implementation of this vulnerability demonstrates a classic buffer overflow scenario where the gets function fails to validate the length of input data against the allocated buffer size. This weakness allows attackers to craft specially formatted input data that exceeds the buffer boundaries, leading to memory corruption that can be manipulated to redirect program execution flow. The vulnerability is particularly concerning because it occurs within a library that is widely used for digital camera raw image processing, meaning numerous applications and systems could be impacted. According to CWE classification, this represents a CWE-121 heap-based buffer overflow, which falls under the category of inadequate input validation and memory safety issues. The attack vector is facilitated through improper handling of data streams during image file processing, making it accessible to threat actors who can upload or otherwise provide malicious input files.
The operational impact of CVE-2021-32142 extends beyond simple privilege escalation to encompass broader system compromise and potential data exfiltration capabilities. When exploited successfully, this vulnerability enables attackers to gain elevated system privileges, potentially allowing them to install malware, modify system files, or establish persistent backdoors within affected systems. The vulnerability affects any system running applications that utilize LibRaw version 0.20.0 for image processing, including but not limited to photo editing software, digital asset management systems, and content management platforms. From an ATT&CK framework perspective, this vulnerability maps to privilege escalation techniques and can be leveraged as part of a broader attack chain that includes initial access through malicious image files or compromised applications that process raw camera formats. The exploitation requires minimal user interaction in many cases, as the vulnerability can be triggered through automated processing of maliciously crafted image files.
Mitigation strategies for CVE-2021-32142 should prioritize immediate patching of affected LibRaw installations to version 0.20.2 or later, which contains the necessary fixes for the buffer overflow condition. System administrators should also implement input validation controls and sandboxing mechanisms around applications that process raw image files, particularly in multi-user environments where privilege escalation could have severe consequences. Network segmentation and access controls should be strengthened to limit exposure of systems that utilize vulnerable LibRaw versions. Additionally, monitoring solutions should be deployed to detect unusual file processing patterns or privilege escalation attempts that could indicate exploitation attempts. The vulnerability highlights the importance of regular security updates and proper code review practices, particularly for libraries that handle untrusted input data. Organizations should also consider implementing application whitelisting policies to restrict execution of potentially vulnerable applications and maintain comprehensive audit logs to track any privilege escalation events that may occur as a result of this vulnerability.