CVE-2012-1162 in libzip
Summary
by MITRE
Heap-based buffer overflow in the _zip_readcdir function in zip_open.c in libzip 0.10 allows remote attackers to cause a denial of service (application crash) and possibly execute arbitrary code via a zip archive with the number of directories set to 0, related to an "incorrect loop construct."
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Analysis
by VulDB Data Team • 03/22/2021
The vulnerability identified as CVE-2012-1162 represents a critical heap-based buffer overflow within the libzip library version 0.10, specifically affecting the _zip_readcdir function in the zip_open.c source file. This flaw manifests when processing malformed zip archives where the number of directories is set to zero, creating a dangerous condition that can be exploited by remote attackers to compromise system integrity. The vulnerability stems from an incorrect loop construct that fails to properly validate input parameters, allowing malicious zip files to trigger memory corruption during archive parsing operations.
The technical implementation of this vulnerability involves a classic buffer overflow scenario where the application attempts to write data beyond the allocated heap memory boundaries. When the _zip_readcdir function processes a zip archive with zero directories, the loop construct that should iterate through directory entries fails to account for this edge case, leading to memory corruption that can result in application crashes or more severe consequences. This type of vulnerability falls under CWE-121, heap-based buffer overflow, which is particularly dangerous because it can be leveraged for arbitrary code execution when properly crafted malicious inputs are processed.
The operational impact of CVE-2012-1162 extends beyond simple denial of service conditions to potentially enable remote code execution capabilities. Attackers can exploit this vulnerability by crafting malicious zip archives that manipulate the directory count field to zero, causing the vulnerable application to allocate insufficient memory for directory entries while still attempting to process them. This creates a condition where subsequent memory operations can overwrite adjacent heap regions, potentially allowing attackers to inject and execute malicious code within the target application's memory space. The vulnerability affects any application that relies on libzip 0.10 for zip archive processing, including web servers, file processing utilities, and content management systems.
Mitigation strategies for this vulnerability require immediate patching of affected libzip installations to version 0.11 or later, where the problematic loop construct has been corrected. System administrators should implement input validation measures to verify zip archive integrity before processing, particularly focusing on directory count fields and overall archive structure. Additionally, deploying intrusion detection systems that can identify suspicious zip file patterns and implementing network segmentation to limit exposure of vulnerable applications can provide additional layers of protection. The ATT&CK framework categorizes this vulnerability under T1203, Exploitation for Client Execution, as it involves exploiting application flaws to execute code remotely. Organizations should also consider implementing application whitelisting policies and regular security assessments to identify other potential vulnerabilities in their software dependencies.