CVE-2002-1096 in VPN 3000 Concentrator
Summary
by MITRE
Cisco VPN 3000 Concentrator 2.2.x, and 3.x before 3.5.1, allows restricted administrators to obtain user passwords that are stored in plaintext in HTML source code.
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Analysis
by VulDB Data Team • 05/16/2019
The vulnerability identified as CVE-2002-1096 affects Cisco VPN 3000 Concentrator appliances running software versions 2.2.x and 3.x prior to 3.5.1. This security flaw represents a critical weakness in the authentication and authorization mechanisms of the VPN concentrator, specifically targeting the privilege escalation capabilities of restricted administrative users. The vulnerability stems from improper access controls that allow users with limited administrative privileges to bypass normal security boundaries and access sensitive information that should remain protected. This issue directly violates fundamental security principles of least privilege and information hiding, creating a significant risk for organizations relying on these devices for network security.
The technical implementation of this vulnerability involves the storage and presentation of user credentials in plaintext within HTML source code, a practice that fundamentally undermines the security of the authentication system. When restricted administrators access certain management interfaces or configuration pages, they can view the raw HTML source code of web-based administrative panels where user passwords are stored in an unencrypted format. This plaintext storage mechanism creates an exploitable condition where unauthorized access to the web interface, combined with basic HTML source code inspection capabilities, allows attackers to extract password information. The vulnerability is particularly concerning because it does not require sophisticated attack techniques or elevated privileges beyond what is already granted to restricted administrators, making it accessible to users who should not have such information access.
The operational impact of CVE-2002-1096 extends beyond simple credential theft, as it represents a fundamental breakdown in the security architecture of the affected Cisco VPN appliances. Organizations utilizing these devices face potential compromise of their entire network security posture, as the extracted passwords can be used to gain unauthorized access to network resources, escalate privileges within the VPN infrastructure, and potentially access other systems within the network perimeter. This vulnerability also creates a persistent risk since the plaintext passwords remain accessible to any user with sufficient privileges to view the HTML source code, meaning that even temporary access could result in permanent credential exposure. The impact is particularly severe for organizations that rely heavily on VPN connectivity for remote access, as the compromise of authentication credentials directly affects their ability to maintain secure remote connections.
The vulnerability aligns with CWE-312 (Cleartext Storage of Sensitive Information) and represents a classic example of poor cryptographic implementation and insecure data handling practices. From an attack perspective, this weakness maps to techniques described in the MITRE ATT&CK framework under T1566 (Phishing for Information) and T1078 (Valid Accounts) where attackers can leverage existing access to extract sensitive information through information gathering techniques. Organizations should implement immediate mitigations including updating to Cisco VPN 3000 Concentrator software version 3.5.1 or later, which addresses the plaintext storage issue through proper credential handling mechanisms. Additionally, network administrators should conduct thorough access control reviews, implement stricter privilege management policies, and consider additional security controls such as encrypted credential storage, regular security audits, and monitoring for unauthorized access attempts to prevent exploitation of this vulnerability.