CVE-2008-3323 in Cygwin
Summary
by MITRE
setup.exe before 2.573.2.3 in Cygwin does not properly verify the authenticity of packages, which allows remote Cygwin mirror servers or man-in-the-middle attackers to execute arbitrary code via a package list containing the MD5 checksum of a Trojan horse package.
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Analysis
by VulDB Data Team • 09/30/2018
The vulnerability identified as CVE-2008-3323 represents a critical security flaw in the Cygwin package management system that persisted through versions prior to 2.573.2.3. This issue fundamentally undermines the integrity of the package verification process by failing to properly authenticate package contents, creating a pathway for malicious actors to compromise systems through compromised package repositories. The vulnerability specifically affects the setup.exe component which serves as the primary package installer and manager for the Cygwin environment on windows systems.
The technical flaw stems from inadequate cryptographic verification mechanisms within the Cygwin setup process. When users attempt to install packages through the Cygwin installer, the system relies on MD5 checksums to verify package integrity. However, the vulnerability allows attackers to manipulate the package list by substituting legitimate package checksums with those of malicious Trojan horse packages. This weakness enables attackers to bypass the expected verification process and execute arbitrary code on target systems. The vulnerability operates at the core of the package management trust model, where the integrity of downloaded packages is assumed based on checksum validation alone without additional authentication mechanisms.
The operational impact of this vulnerability extends beyond simple code execution to encompass complete system compromise. Remote attackers capable of intercepting network traffic or compromising Cygwin mirror servers can exploit this weakness to deliver malicious packages that appear legitimate to the system. This creates a significant risk for organizations relying on Cygwin for development environments, as compromised packages could provide attackers with persistent access to systems or enable the installation of backdoors, rootkits, or other malicious software. The vulnerability particularly affects environments where automatic package updates occur, as these automated processes may silently install compromised software without user intervention.
From a cybersecurity perspective, this vulnerability aligns with several ATT&CK techniques including T1195.002 (Supply Chain Compromise) and T1059.001 (Command and Scripting Interpreter) where attackers manipulate legitimate software delivery mechanisms to execute malicious code. The weakness also corresponds to CWE-347 (Improper Verification of Cryptographic Signature) and CWE-22 (Path Traversal) as it involves inadequate signature verification and potential path manipulation in package installation processes. Organizations should implement immediate mitigation strategies including verifying package signatures through trusted channels, implementing network monitoring to detect suspicious package modifications, and upgrading to Cygwin versions that properly validate package authenticity. The vulnerability demonstrates the critical importance of multi-layered security approaches where checksum validation alone is insufficient for protecting against sophisticated attacks targeting software supply chains.