CVE-2002-1105 in VPN Client
Summary
by MITRE
Cisco Virtual Private Network (VPN) Client software 2.x.x, and 3.x before 3.5.1C, allows local users to use a utility program to obtain the group password.
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Analysis
by VulDB Data Team • 04/19/2019
The vulnerability identified as CVE-2002-1105 affects Cisco Virtual Private Network VPN Client software versions 2.x.x and 3.x prior to 3.5.1C, representing a significant security flaw that undermines the integrity of remote access authentication mechanisms. This issue stems from improper handling of group password storage and retrieval within the client software, creating a pathway for local users to exploit the system through a utility program designed for administrative purposes. The vulnerability resides in the client-side configuration management where sensitive authentication credentials are stored in a manner that can be accessed by unauthorized local entities without proper authorization.
The technical flaw manifests through the insecure storage of group passwords within the VPN client configuration files, which are accessible to local users who can execute utility programs that bypass normal authentication procedures. This represents a classic case of weak credential storage and insufficient access controls, falling under the CWE-312 category of "Cleartext Storage of Sensitive Information." The vulnerability allows local attackers to extract group passwords from the client configuration, potentially enabling them to establish unauthorized VPN connections to protected networks. The flaw exists because the software does not adequately protect sensitive data through proper encryption or access control mechanisms, making the group password readily available to any user with local system access.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it enables local users to gain unauthorized network access to corporate resources that would normally require proper authentication. This creates a substantial risk for organizations that rely on VPN client software for secure remote access, as a single compromised local account can provide access to the entire network infrastructure protected by the vulnerable client software. The vulnerability can be exploited by attackers who have already gained local system access, potentially through phishing attacks, social engineering, or other initial compromise techniques. This represents a critical weakness in the defense-in-depth strategy, as the vulnerability allows lateral movement within the network once initial access has been established.
Organizations should immediately implement mitigations including upgrading to Cisco VPN Client software versions 3.5.1C or later, which address this vulnerability through improved credential storage mechanisms and enhanced access controls. System administrators should also conduct thorough security assessments to identify all systems running vulnerable versions of the software and ensure proper network segmentation to limit the impact of potential exploitation. The vulnerability aligns with ATT&CK technique T1550.002 "Use Alternate Authentication Material: Pass the Hash" and represents a failure to implement proper privilege separation and credential protection mechanisms. Additionally, organizations should consider implementing additional monitoring and logging of VPN client activities to detect potential exploitation attempts and maintain audit trails for security incident response activities.