CVE-2017-11190 in unrar-free
Summary
by MITRE
unrarlib.c in unrar-free 0.0.1, when _DEBUG_LOG mode is enabled, might allow remote attackers to cause a denial of service (stack-based buffer overflow and application crash) or possibly have unspecified other impact via an RAR archive containing a long filename.
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Analysis
by VulDB Data Team • 03/05/2025
The vulnerability identified as CVE-2017-11190 affects the unrar-free library version 0.0.1 and represents a critical stack-based buffer overflow condition that can be exploited through maliciously crafted RAR archives. This flaw specifically manifests when the library operates in _DEBUG_LOG mode, a debugging feature designed for development and testing purposes but inadvertently creates a security risk when deployed in production environments. The vulnerability stems from inadequate input validation and bounds checking within the filename processing routine, where the unrarlib.c component fails to properly validate the length of filenames contained within RAR archives before attempting to store them in fixed-size buffers on the stack.
The technical exploitation of this vulnerability occurs when an attacker crafts a RAR archive containing an excessively long filename that exceeds the allocated buffer size in the unrar-free library. When the library processes this archive with debugging enabled, the malformed filename causes a stack-based buffer overflow that corrupts adjacent memory locations and ultimately leads to application crash or potential arbitrary code execution depending on the specific system configuration and memory layout. This type of vulnerability falls under the Common Weakness Enumeration category CWE-121, which specifically addresses stack-based buffer overflow conditions, and aligns with the ATT&CK framework's technique T1059.007 for command and scripting interpreter execution through file format manipulation.
The operational impact of this vulnerability extends beyond simple denial of service scenarios as it can be leveraged for more sophisticated attacks when combined with other exploitation techniques. Remote attackers can utilize this vulnerability to disrupt services by causing application crashes, potentially leading to system instability or complete service outages. In environments where unrar-free is used for automated processing of user-uploaded content or file transfers, this vulnerability creates a significant risk for attackers seeking to compromise system availability. The vulnerability is particularly concerning because it can be triggered through legitimate file processing operations, making it difficult to detect and prevent through traditional network monitoring approaches. Organizations using this library in production systems without proper input validation measures face increased risk of service disruption and potential data integrity issues.
Mitigation strategies for CVE-2017-11190 should focus on immediate remediation through library updates or patches provided by the maintainers, as well as implementing defensive programming practices to prevent similar issues in custom code. System administrators should disable _DEBUG_LOG mode in production environments and ensure that all file processing operations include proper input validation and length checking before processing potentially malicious content. The implementation of sandboxed execution environments for file processing, input sanitization measures, and regular security audits of third-party libraries can significantly reduce the risk exposure associated with this vulnerability. Additionally, organizations should consider implementing network segmentation and monitoring to detect unusual file processing patterns that might indicate exploitation attempts. The vulnerability demonstrates the importance of proper memory management and input validation in security-critical libraries, emphasizing the need for comprehensive testing including fuzzing and boundary condition testing to identify similar issues before they can be exploited in real-world scenarios.