CVE-2015-2019 in Tivoli Security Directory Server
Summary
by MITRE
IBM Tivoli Security Directory Server 6.0 before iFix 75, 6.1 before iFix 68, 6.2 before iFix 44, 6.3 before iFix 37, 6.3.1 before iFix 11, and 6.4 before iFix 2 does not preventing caching of documents retrieved in SSL sessions, which allows physically proximate attackers to obtain sensitive information by leveraging an unattended workstation.
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Analysis
by VulDB Data Team • 05/22/2022
The vulnerability identified as CVE-2015-2019 affects IBM Tivoli Security Directory Server versions across multiple release lines including 6.0 through 6.4, specifically before their respective iFix patches were applied. This security flaw represents a critical issue in the server's handling of SSL sessions and document caching mechanisms. The vulnerability stems from the server's failure to properly prevent caching of documents retrieved during SSL sessions, creating a significant information disclosure risk. The flaw is particularly concerning because it can be exploited by attackers who are physically proximate to an unattended workstation, making it a vector for insider threats or opportunistic attacks in shared environments.
The technical implementation of this vulnerability resides in the server's SSL session management and caching subsystems. When SSL sessions are established, documents and data retrieved during these sessions should not be cached in a manner that could expose sensitive information to unauthorized parties. However, the affected IBM Tivoli Security Directory Server versions fail to properly isolate cached content from subsequent session access, allowing cached documents to persist in memory or storage areas where they can be accessed by other processes or users. This design flaw creates a cache timing attack surface where sensitive directory information, authentication credentials, or other privileged data could be retrieved from cached session content.
The operational impact of this vulnerability extends beyond simple information disclosure to encompass potential privilege escalation and unauthorized access to sensitive directory services. Attackers who gain physical proximity to an unattended workstation running the vulnerable server can exploit this weakness to retrieve cached documents that may contain user credentials, access control information, or other sensitive data that was previously accessed during SSL sessions. This threat model aligns with attack techniques described in the ATT&CK framework under credential access and privilege escalation tactics, where adversaries leverage system weaknesses to obtain unauthorized access to sensitive information. The vulnerability is particularly dangerous in enterprise environments where workstations may be left unattended during business hours, creating persistent exposure windows for attackers.
From a compliance and security standards perspective, this vulnerability directly relates to CWE-200, which addresses exposure of sensitive information, and CWE-312, which covers exposure of sensitive data through improper caching. The vulnerability also maps to ATT&CK techniques such as credential access through cached credentials and privilege escalation via system weaknesses. Organizations using IBM Tivoli Security Directory Server should immediately implement the applicable iFix patches for their specific version to address this vulnerability. Additionally, network segmentation, workstation security policies requiring automatic lock screens, and monitoring for unauthorized physical access should be implemented as compensating controls. The vulnerability highlights the importance of proper session management and cache isolation in security-critical applications, particularly those handling sensitive directory and authentication information. Organizations should also conduct vulnerability assessments to identify other potential caching issues within their directory services infrastructure and ensure that all systems maintain proper isolation between cached content and sensitive data access.