CVE-2017-12858 in libzip
Summary
by MITRE
Double free vulnerability in the _zip_dirent_read function in zip_dirent.c in libzip allows attackers to have unspecified impact via unknown vectors.
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Analysis
by VulDB Data Team • 12/16/2022
The vulnerability identified as CVE-2017-12858 represents a critical double free condition within the libzip library's zip_dirent.c component, specifically in the _zip_dirent_read function. This flaw constitutes a memory corruption vulnerability that arises from improper memory management practices during the processing of zip archive entries. The double free vulnerability occurs when the same memory block is freed twice during the execution of the function, creating a potential exploitation vector that could lead to arbitrary code execution or denial of service conditions.
The technical nature of this vulnerability stems from the improper handling of memory allocation and deallocation within the zip archive parsing logic. When processing certain malformed or crafted zip files, the _zip_dirent_read function fails to properly validate the state of memory blocks before attempting to free them, resulting in the same memory address being passed to the free() function multiple times. This condition violates fundamental memory management principles and creates opportunities for attackers to manipulate the heap structure, potentially leading to code execution or system instability.
From an operational perspective, this vulnerability poses significant risks to systems that utilize libzip for processing untrusted zip files, including web applications, file processing services, and archive management systems. The unspecified impact mentioned in the CVE description reflects the potential for various malicious outcomes depending on the exploitation context and system configuration. Attackers could leverage this vulnerability to execute arbitrary code on vulnerable systems, potentially leading to complete system compromise, data exfiltration, or service disruption. The vulnerability's impact extends beyond simple denial of service scenarios, as heap corruption can be exploited to manipulate program execution flow through techniques such as return-oriented programming or heap spraying.
The vulnerability aligns with CWE-415, which describes improper handling of memory allocation and deallocation leading to double free conditions. This weakness is particularly concerning in the context of the ATT&CK framework's defense evasion and privilege escalation tactics, as successful exploitation could enable attackers to bypass security controls and gain elevated system privileges. The vulnerability affects systems that depend on libzip for zip file processing, including but not limited to web servers, email systems, and content management platforms that handle user-uploaded zip archives. Organizations using vulnerable versions of libzip should prioritize immediate remediation through patch updates or alternative processing mechanisms.
Mitigation strategies should include immediate patching of affected libzip versions, implementing strict input validation for zip file processing, and deploying runtime protections such as address space layout randomization and stack canaries. Additionally, organizations should consider implementing network segmentation and monitoring for suspicious zip file processing activities. The vulnerability demonstrates the critical importance of proper memory management in security-critical libraries and underscores the need for comprehensive code review processes and automated testing for memory safety issues. Regular security assessments and vulnerability scanning should be implemented to identify and remediate similar issues in other components of the software supply chain.