CVE-2011-1317 in WebSphere Application Server
Summary
by MITRE
Memory leak in com.ibm.ws.jsp.runtime.WASJSPStrBufferImpl in the JavaServer Pages (JSP) component in IBM WebSphere Application Server (WAS) 6.1.0.x before 6.1.0.37 and 7.x before 7.0.0.15 allows remote attackers to cause a denial of service (memory consumption) by sending many JSP requests that trigger large responses.
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Analysis
by VulDB Data Team • 10/19/2021
The vulnerability identified as CVE-2011-1317 represents a critical memory leak flaw within IBM WebSphere Application Server's JavaServer Pages component. This issue affects versions 6.1.0.x prior to 6.1.0.37 and 7.x prior to 7.0.0.15, where the com.ibm.ws.jsp.runtime.WASJSPStrBufferImpl class fails to properly manage memory allocation during JSP request processing. The flaw manifests when the application server handles multiple JSP requests that generate large response payloads, leading to progressive memory consumption that ultimately results in system instability and denial of service conditions.
The technical root cause of this vulnerability resides in improper memory management within the JSP runtime environment. When the WASJSPStrBufferImpl class processes large JSP responses, it allocates memory buffers to handle string operations but fails to release these memory resources properly after processing. This memory leak occurs repeatedly with each JSP request that generates substantial output, causing the application server's memory footprint to grow continuously over time. The vulnerability specifically targets the string buffer implementation used internally by the JSP engine, making it particularly effective when processing large dynamic content or complex JSP pages that produce extensive output.
From an operational perspective, this vulnerability presents a significant risk to web application availability and system performance. Attackers can exploit this flaw by sending numerous JSP requests that trigger large response generation, causing the WebSphere Application Server to consume increasing amounts of memory until system resources are exhausted. The impact extends beyond simple resource exhaustion, as the memory leak can lead to application server crashes, degraded performance for legitimate users, and potential system-wide instability. This makes the vulnerability particularly dangerous in production environments where high availability and consistent performance are critical requirements.
The vulnerability aligns with CWE-401, which categorizes memory leaks as a fundamental weakness in software design that can lead to resource exhaustion and system instability. From an adversarial perspective, this flaw maps to several ATT&CK tactics including privilege escalation and denial of service, as attackers can leverage the memory leak to consume system resources and potentially disrupt service availability. Organizations running affected WebSphere versions should prioritize patching and monitoring for this vulnerability, as the memory consumption pattern can be difficult to detect until it reaches critical levels. The remediation strategy involves applying the official IBM patches that address the memory management issues in the JSP runtime component, along with implementing monitoring solutions to detect unusual memory consumption patterns that may indicate exploitation attempts.