CVE-2018-1000034 in UnZIP
Summary
by MITRE
An out-of-bounds read exists in InfoZip UnZip version 6.10c22 that allows an attacker to perform a denial of service and read sensitive memory.
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Analysis
by VulDB Data Team • 01/03/2020
The vulnerability identified as CVE-2018-1000034 represents a critical out-of-bounds read flaw within InfoZip UnZip version 6.10c22 that fundamentally compromises the software's memory safety mechanisms. This issue arises from insufficient input validation during the processing of compressed archive files, specifically when handling malformed or crafted archive entries that exceed expected buffer boundaries. The flaw manifests when the unzip utility attempts to read memory locations beyond the allocated buffer space, creating potential avenues for both denial of service attacks and unauthorized memory access that could expose sensitive data.
The technical implementation of this vulnerability stems from improper boundary checking within the decompression routines of the unzip utility. When processing archive files containing specially crafted data structures, the software fails to validate the length and structure of compressed data before attempting to read from memory locations. This condition creates a scenario where the program attempts to access memory addresses that may contain confidential information, user data, or system resources that should remain protected. The vulnerability is classified under CWE-129 as an insufficient validation of length of a buffer, while also mapping to CWE-125 for out-of-bounds read conditions that can lead to information disclosure.
From an operational perspective, this vulnerability presents significant risks to organizations relying on InfoZip UnZip for archive management and file extraction processes. Attackers can exploit this flaw by creating malicious archive files that trigger the out-of-bounds read condition, resulting in application crashes or system instability that constitutes a denial of service. More critically, the memory read operations may inadvertently expose sensitive information stored in adjacent memory locations, potentially including passwords, encryption keys, or other confidential data that resides in the program's memory space. The impact extends beyond simple service disruption to include potential data leakage that could compromise system security and confidentiality.
Security practitioners should implement immediate mitigations including upgrading to patched versions of InfoZip UnZip where available, as the vulnerability affects a widely used decompression utility across multiple operating systems and platforms. Organizations should also consider implementing additional defensive measures such as input sanitization for archive files, network-based filtering of suspicious archive content, and runtime monitoring for abnormal memory access patterns. The vulnerability aligns with ATT&CK technique T1059.007 for execution through decompression tools and T1566 for initial access through malicious file attachments, making it particularly relevant for organizations implementing comprehensive threat detection and response strategies. Regular security assessments should include verification of unzip utility versions and configuration to prevent exploitation of this memory safety vulnerability that could serve as a gateway for more sophisticated attacks.