CVE-2006-2856 in ActivePerl
Summary
by MITRE
ActiveState ActivePerl 5.8.8.817 for Windows configures the site/lib directory with "Users" group permissions for changing files, which allows local users to gain privileges by creating a malicious sitecustomize.pl file in that directory. NOTE: The provenance of this information is unknown; the details are obtained solely from third party information.
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Analysis
by VulDB Data Team • 07/28/2018
This vulnerability exists in ActiveState ActivePerl 5.8.8.817 for Windows where the site/lib directory is configured with insufficient access controls that grant the "Users" group write permissions. The technical flaw stems from improper privilege assignment during the installation process, creating a path traversal and code injection vector that directly enables privilege escalation. The vulnerability is classified as a privilege escalation issue under CWE-264, specifically involving improper access control mechanisms that allow unauthorized modification of critical system components.
The operational impact of this vulnerability is significant as it provides local attackers with a straightforward method to escalate their privileges from standard user level to a higher privilege level. By creating a malicious sitecustomize.pl file in the compromised directory, an attacker can execute arbitrary code with elevated permissions, effectively bypassing normal security boundaries. This represents a classic local privilege escalation attack pattern that aligns with ATT&CK technique T1068, which focuses on local privilege escalation through exploitation of system weaknesses.
The vulnerability exploits the Perl interpreter's module loading mechanism where sitecustomize.pl files are automatically executed during Perl startup, making it an ideal location for persistent code injection. The issue demonstrates poor security hardening practices where default installation configurations fail to implement least privilege principles, allowing users to modify core system components. This weakness creates a persistent backdoor that can be leveraged for further attack progression, including potential lateral movement within the compromised system.
Mitigation strategies should focus on immediate privilege restriction by removing write permissions from the Users group for the site/lib directory. System administrators should implement proper access control lists and ensure that only authorized personnel have write access to critical system directories. Regular security audits should verify proper privilege assignment and monitor for unauthorized modifications to system components. Additionally, organizations should consider implementing application whitelisting policies that restrict execution of unauthorized Perl modules, and establish proper patch management processes to ensure timely updates of vulnerable software components. The vulnerability underscores the importance of proper privilege management and access control implementation in preventing local privilege escalation attacks.