CVE-2013-6734 in WebSphere eXtreme Scale Client
Summary
by MITRE
IBM WebSphere eXtreme Scale Client 7.1 through 8.6.0.4 does not properly isolate the cached data of different users, which allows remote authenticated users to obtain sensitive information in opportunistic circumstances by leveraging access to the same web container.
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Analysis
by VulDB Data Team • 03/01/2018
IBM WebSphere eXtreme Scale Client contains a critical information disclosure vulnerability that stems from inadequate data isolation mechanisms within its caching infrastructure. This vulnerability affects versions 7.1 through 8.6.0.4 of the client software and represents a classic case of insufficient access control implementation where cached data intended for one user becomes accessible to other authenticated users within the same web container environment. The flaw manifests when multiple users share the same application server instance or web container, creating a scenario where cached data objects are not properly segregated based on user context or session identifiers.
The technical implementation of this vulnerability involves the client's failure to maintain proper cache partitioning between different user sessions. When the eXtreme Scale client caches data objects for various users within the same container, it does not adequately distinguish between different user contexts, leading to potential cross-contamination of cached information. This weakness occurs at the application level where cache keys or identifiers do not incorporate sufficient user-specific attributes to ensure complete isolation. The vulnerability is particularly concerning because it operates opportunistically, meaning that an attacker only needs to be authenticated to the same application server instance as the target user to potentially access sensitive cached data.
From an operational perspective, this vulnerability creates significant risk for organizations deploying IBM WebSphere eXtreme Scale in multi-tenant or shared hosting environments where multiple users or applications may operate within the same web container. The impact extends beyond simple data leakage to potentially expose sensitive user information including personal data, financial records, or confidential business information that may be cached for performance optimization purposes. Attackers can exploit this vulnerability through legitimate authenticated access to the web container, making detection more challenging as the activity appears to be normal user behavior within the application environment.
The vulnerability aligns with CWE-200, which addresses "Information Exposure," and specifically relates to improper information handling within shared computing environments. From an ATT&CK framework perspective, this vulnerability maps to techniques involving credential access and information gathering, where adversaries leverage legitimate access to extract sensitive data from improperly isolated cache mechanisms. The opportunistic nature of this flaw means that attackers do not require specialized tools or privileged access beyond standard authentication credentials, making it particularly dangerous in environments where user authentication is relatively straightforward to obtain.
Organizations should implement immediate mitigations including ensuring proper cache isolation mechanisms are configured for user-specific data, implementing additional access controls beyond the basic authentication layer, and considering the deployment of separate web containers or application server instances for different user groups when possible. Regular security assessments should verify that caching mechanisms properly implement user context separation, and organizations should consider implementing monitoring solutions to detect anomalous access patterns that may indicate cache data leakage. The vulnerability also underscores the importance of following secure coding practices for caching implementations and adhering to the principle of least privilege in shared hosting environments.