CVE-2011-1318 in WebSphere Application Server
Summary
by MITRE
Memory leak in org.apache.jasper.runtime.JspWriterImpl.response in the JavaServer Pages (JSP) component in IBM WebSphere Application Server (WAS) before 7.0.0.15 allows remote attackers to cause a denial of service (memory consumption) by accessing a JSP page of an application that is repeatedly stopped and restarted.
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Analysis
by VulDB Data Team • 10/19/2021
The vulnerability identified as CVE-2011-1318 represents a critical memory leak flaw within the JavaServer Pages component of IBM WebSphere Application Server. This issue specifically affects the org.apache.jasper.runtime.JspWriterImpl.response class which handles response output streaming in JSP processing. The vulnerability manifests when applications utilizing JSP pages undergo repeated stop and restart operations, creating a condition where memory allocated for response handling is not properly released back to the system. This memory consumption pattern directly impacts the server's ability to maintain stable operations over extended periods.
The technical root cause of this vulnerability stems from improper resource management within the JSP writer implementation. When JSP pages are repeatedly stopped and restarted, the JspWriterImpl.response component fails to properly dispose of allocated memory buffers and internal data structures. This memory leak occurs because the garbage collection mechanism cannot effectively reclaim memory that remains referenced by objects in the response handling chain. The flaw is particularly insidious because it accumulates over time, with each application restart contributing to additional memory consumption that compounds the issue.
From an operational perspective, this vulnerability creates significant denial of service conditions that can severely impact application availability and system performance. Attackers can exploit this weakness by repeatedly accessing JSP pages within an application, triggering the stop and restart cycles that perpetuate the memory leak. As memory consumption increases, the application server experiences degraded performance, potential out-of-memory errors, and ultimately may become unresponsive to legitimate requests. The cumulative effect of this memory leak can lead to complete system failure or forced restarts that disrupt business operations.
The impact of this vulnerability aligns with CWE-401, which catalogs memory leak issues in software systems, and demonstrates characteristics consistent with ATT&CK technique T1499.004 for resource exhaustion attacks. Organizations deploying IBM WebSphere Application Server versions prior to 7.0.0.15 face substantial risk of service disruption when this vulnerability is exploited. The vulnerability affects not only individual applications but potentially the entire application server instance, making it a critical concern for enterprise environments where high availability and consistent performance are essential. The exploitation requires minimal privileges and can be automated, making it particularly dangerous in production environments.
Mitigation strategies should focus on immediate patch application to IBM WebSphere Application Server version 7.0.0.15 or later, which contains the necessary fixes for the memory leak issue. Organizations should also implement monitoring solutions that track memory consumption patterns and alert administrators to unusual memory usage trends. Additionally, application design should minimize the frequency of JSP page stop and restart operations, and administrators should consider implementing application server resource limits and memory management policies to prevent complete system exhaustion. Regular security assessments and vulnerability scanning should include verification of patched versions to ensure complete remediation of this memory leak vulnerability.