CVE-2018-7727 in ZZIPlib
Summary
by MITRE
An issue was discovered in ZZIPlib 0.13.68. There is a memory leak triggered in the function zzip_mem_disk_new in memdisk.c, which will lead to a denial of service attack.
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Analysis
by VulDB Data Team • 07/10/2025
The vulnerability identified as CVE-2018-7727 represents a critical memory management flaw within ZZIPlib version 0.13.68, a widely used library for handling zip file archives in various software applications. This memory leak occurs specifically within the zzip_mem_disk_new function located in the memdisk.c source file, demonstrating a fundamental failure in resource allocation and deallocation mechanisms that can severely compromise system stability and availability.
The technical implementation of this vulnerability stems from improper memory handling within the zzip_mem_disk_new function which is responsible for creating memory-based disk structures for zip file operations. When processing certain archive files, the function fails to properly release allocated memory blocks, creating a gradual accumulation of unused memory segments that persist throughout the application lifecycle. This memory consumption pattern directly violates established software engineering principles and security best practices, as it creates a predictable resource exhaustion scenario that attackers can exploit to disrupt normal system operations. The vulnerability manifests as a progressive memory leak that intensifies with continued use of the affected library, making it particularly dangerous in long-running applications or services that frequently process zip archives.
From an operational impact perspective, this vulnerability creates a significant denial of service condition that can affect any application or system utilizing ZZIPlib 0.13.68 for zip file processing. The memory leak can gradually consume available system resources, leading to application crashes, system slowdowns, or complete system unresponsiveness. Attackers can exploit this weakness by submitting malicious or specially crafted zip files that trigger the memory leak during processing, effectively creating a resource exhaustion attack that can be sustained over time. This makes the vulnerability particularly dangerous in server environments, web applications, or any automated systems that process user-provided zip files without proper input validation or resource monitoring. The vulnerability's impact extends beyond immediate service disruption to potentially compromise system availability and reliability, especially in environments where multiple concurrent processes are utilizing the affected library.
Mitigation strategies for CVE-2018-7727 should prioritize immediate library updates to versions that have addressed the memory leak issue, as this represents the most effective and straightforward solution. System administrators should implement comprehensive monitoring of memory usage patterns in applications that utilize ZZIPlib to detect early signs of memory consumption anomalies that may indicate exploitation attempts. Additionally, input validation measures should be strengthened to prevent processing of malformed or suspicious zip files, while implementing resource limits and timeouts on archive processing operations to minimize the impact of potential exploitation attempts. Organizations should also consider implementing network segmentation and access controls to limit exposure of systems that process user-provided zip files, thereby reducing the attack surface for this particular vulnerability. The vulnerability aligns with CWE-401, which specifically addresses improper release of memory, and represents a clear violation of ATT&CK technique T1499.004 for network denial of service attacks through resource exhaustion.