CVE-2018-9058 in Long Range Zip
Summary
by MITRE
In Long Range Zip (aka lrzip) 0.631, there is an infinite loop in the runzip_fd function of runzip.c. Remote attackers could leverage this vulnerability to cause a denial of service via a crafted lrz file.
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Analysis
by VulDB Data Team • 02/24/2023
The vulnerability identified as CVE-2018-9058 affects Long Range Zip (lrzip) version 0.631, a compression utility designed for handling large files with high compression ratios. This flaw manifests as an infinite loop within the runzip_fd function located in the runzip.c source file, representing a critical denial of service vulnerability that can be exploited remotely. The issue arises when processing specially crafted lrz files that trigger malformed data handling within the decompression routine.
The technical root cause of this vulnerability stems from insufficient input validation and boundary checking within the runzip_fd function. When the decompression process encounters malformed or specially crafted data structures within the lrz file format, the function fails to properly terminate its processing loop, resulting in indefinite execution. This behavior constitutes a classic infinite loop vulnerability that consumes system resources and prevents normal operation of the decompression process. The flaw specifically impacts the decompression workflow where the program enters a state where it continuously processes data without making forward progress, effectively hanging the application.
From an operational perspective, this vulnerability presents a significant risk to systems that rely on lrzip for file decompression, particularly in environments where automated processing or remote file handling occurs. Remote attackers can exploit this weakness by crafting malicious lrz files that, when processed by vulnerable lrzip versions, cause the decompression utility to enter an infinite loop. This leads to complete denial of service conditions where legitimate users cannot decompress files, and system resources become consumed by the hanging process. The impact extends beyond simple service interruption as the infinite loop can cause system instability, resource exhaustion, and potential system crashes depending on the execution environment.
The vulnerability aligns with CWE-835, which specifically addresses the issue of infinite loops in software systems, and represents a clear violation of proper input validation principles. From an attack methodology standpoint, this vulnerability maps to the ATT&CK technique T1499.004, which covers the exploitation of resource exhaustion through denial of service attacks. The flaw demonstrates poor defensive programming practices where the decompression routine lacks proper termination conditions and input sanitization mechanisms. Systems utilizing lrzip for automated file processing, backup operations, or file transfer protocols are particularly vulnerable to this attack vector.
Mitigation strategies for CVE-2018-9058 should focus on immediate patching of lrzip to version 0.632 or later, which contains the necessary fixes for the infinite loop condition. Organizations should implement input validation measures for lrz files, particularly when processing untrusted content, and consider deploying sandboxing techniques to isolate decompression operations. Network-level defenses such as content filtering and file type validation can provide additional protection layers. System administrators should monitor for unusual resource consumption patterns that might indicate exploitation attempts. Regular security assessments of compression utilities and input validation procedures should be conducted to prevent similar vulnerabilities from emerging in other components of the system infrastructure.