CVE-2018-10027 in ALZip
Summary
by MITRE
ESTsoft ALZip before 10.76 allows local users to execute arbitrary code via creating a malicious .DLL file and installing it in a specific directory: %PROGRAMFILES%\ESTsoft\ALZip\Formats, %PROGRAMFILES%\ESTsoft\ALZip\Coders, %PROGRAMFILES(X86)%\ESTsoft\ALZip\Formats, or %PROGRAMFILES(X86)%\ESTsoft\ALZip\Coders.
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Analysis
by VulDB Data Team • 02/06/2020
This vulnerability resides in ESTsoft ALZip versions prior to 10.76 and represents a classic privilege escalation flaw that enables local attackers to execute arbitrary code through malicious dynamic link library files. The vulnerability stems from the application's improper handling of plugin modules and third-party components that are loaded during archive processing operations. Attackers can exploit this weakness by placing a specially crafted malicious .dll file in specific directories within the ALZip installation path, effectively bypassing normal security controls and gaining elevated privileges within the system context.
The technical exploitation mechanism relies on the application's automatic loading of DLL files from predetermined directories without proper validation or integrity checks. When ALZip processes archives containing malicious plugins, it automatically loads these components from the designated directories including both x86 and x64 program files locations. This behavior aligns with CWE-427 Uncontrolled Search Path Element, where the application's search path contains elements that are not properly validated or sanitized. The vulnerability creates a dangerous condition where user-controlled DLL files can be loaded with the privileges of the running ALZip process, potentially leading to complete system compromise.
The operational impact of this vulnerability extends beyond simple code execution to encompass full system compromise and persistent access. Local attackers with basic user privileges can leverage this flaw to gain elevated system rights, making it particularly dangerous in multi-user environments where standard users might have access to ALZip functionality. The attack vector is straightforward yet effective, requiring only the ability to write files to the specified program directories. This weakness can be exploited through various methods including social engineering to convince users to process malicious archives or by directly placing the malicious files in the target directories.
Security professionals should recognize this vulnerability as a prime example of poor privilege separation and insecure component loading practices. The flaw demonstrates how applications that dynamically load third-party components without proper security controls can become attack vectors for privilege escalation. Organizations should implement immediate mitigations including updating to ALZip version 10.76 or later, which addresses the vulnerability through proper DLL validation mechanisms. System administrators should also consider implementing file system permissions that restrict write access to the vulnerable directories and monitor for unauthorized DLL installations. Additionally, this vulnerability maps to ATT&CK technique T1059 Command and Scripting Interpreter and T1068 Exploitation for Privilege Escalation, making it a significant concern for defensive security operations and incident response procedures.