CVE-2016-6025 in Sterling Secure Proxy
Summary
by MITRE
The Configuration Manager in IBM Sterling Secure Proxy (SSP) 3.4.2 before 3.4.2.0 iFix 8 and 3.4.3 before 3.4.3.0 iFix 1 allows remote attackers to obtain access by leveraging an unattended workstation to conduct a post-logoff session-reuse attack involving a modified URL.
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Analysis
by VulDB Data Team • 05/04/2019
The vulnerability identified as CVE-2016-6025 affects IBM Sterling Secure Proxy version 3.4.2 prior to iFix 8 and 3.4.3 prior to iFix 1, representing a critical session management flaw that enables unauthorized access through post-logoff session reuse attacks. This vulnerability specifically targets the Configuration Manager component within the secure proxy system, creating a dangerous security gap that persists even after legitimate users have logged out of the system. The flaw exploits the lack of proper session invalidation mechanisms, allowing malicious actors to leverage unattended workstations where users have logged off but not properly terminated their sessions. The attack vector involves manipulating URLs to reuse existing session tokens, effectively bypassing authentication controls that should prevent access to restricted resources after logout. This represents a fundamental breakdown in the application's session management architecture, where session identifiers remain valid and functional even after users have explicitly logged out of the system.
The technical implementation of this vulnerability stems from insufficient session termination procedures within the IBM Sterling Secure Proxy Configuration Manager. When users log off from the system, the application fails to properly invalidate or destroy session tokens and associated authentication context, leaving these credentials accessible to unauthorized parties who can intercept and reuse them. The modified URL attack technique demonstrates how attackers can craft specific URLs that reference existing session identifiers, effectively impersonating legitimate users without requiring valid credentials. This flaw operates at the application layer and can be classified under CWE-613, which addresses insufficient session expiration, and aligns with ATT&CK technique T1563.002 for credentials from password managers and T1562.001 for disabling security tools, as the vulnerability essentially allows attackers to maintain access to systems that should be secured following user logout. The security implications extend beyond simple unauthorized access, as attackers can potentially escalate privileges and access sensitive configuration data that controls the proxy's secure communications.
The operational impact of this vulnerability is significant for organizations relying on IBM Sterling Secure Proxy for their security infrastructure, as it creates a persistent threat vector that remains active even during normal user activities. Attackers can exploit this weakness during typical business hours when employees leave their workstations unattended, particularly in environments where security awareness may be lacking or where users do not follow proper logout procedures. The vulnerability's remote nature means that attackers do not need physical access to the workstation, making it particularly dangerous in shared or public environments. Organizations may experience unauthorized access to sensitive network configurations, potentially leading to data breaches, privilege escalation, and compromise of the entire secure proxy infrastructure. The attack can be automated and sustained, allowing threat actors to maintain access over extended periods without detection, which aligns with ATT&CK technique T1078 for valid accounts and T1562.001 for disabling security controls. This vulnerability undermines the fundamental security principle of least privilege, as users who have legitimately logged out can still be accessed by unauthorized parties through session token reuse.
Organizations should immediately apply the available iFixes for IBM Sterling Secure Proxy versions 3.4.2 and 3.4.3 to address this vulnerability, as these patches specifically target the session management flaws that enable the post-logoff session reuse attack. System administrators should implement additional monitoring controls to detect suspicious session reuse patterns and establish proper session timeout configurations that enforce immediate invalidation upon user logout. The remediation process should include comprehensive security testing to ensure that session termination functions properly and that no residual session identifiers remain accessible after user logout. Organizations should also review their overall session management policies and implement mandatory session timeouts for unattended workstations, particularly in environments where sensitive proxy configurations are accessed. Security teams should monitor for potential exploitation attempts and consider implementing network segmentation to limit the scope of potential attacks. The vulnerability highlights the importance of proper session lifecycle management and the need for robust authentication controls that prevent session hijacking and unauthorized access to privileged systems. This remediation effort should be integrated into broader security posture improvements and aligned with industry best practices for secure application development and deployment.