CVE-2011-3375 in Tomcat
Summary
by MITRE
Apache Tomcat 6.0.30 through 6.0.33 and 7.x before 7.0.22 does not properly perform certain caching and recycling operations involving request objects, which allows remote attackers to obtain unintended read access to IP address and HTTP header information in opportunistic circumstances by reading TCP data.
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Analysis
by VulDB Data Team • 03/20/2021
The vulnerability identified as CVE-2011-3375 represents a critical information disclosure flaw within Apache Tomcat web server implementations. This issue affects versions ranging from 6.0.30 through 6.0.33 and all prior 7.x versions before 7.0.22, making it a widespread concern across multiple major releases of the popular Java application server. The flaw stems from inadequate handling of request object caching and recycling mechanisms, creating a window for malicious actors to exploit temporal inconsistencies in memory management.
The technical root cause of this vulnerability lies in how Tomcat manages request objects during the processing lifecycle. When request objects are cached and recycled for subsequent requests, the system fails to properly clear sensitive information from memory locations that may still be accessible to concurrent or subsequent requests. This improper memory management creates a scenario where HTTP headers and IP address information from one request can persist in memory and be inadvertently exposed to other requests. The vulnerability operates under the principle of information leakage through memory artifacts, which aligns with CWE-200 (Information Exposure) and CWE-1277 (Improper Handling of Memory Allocation Failures).
The operational impact of this vulnerability extends beyond simple information disclosure, creating potential avenues for sophisticated attacks that can harvest sensitive network and application metadata. Remote attackers can exploit this weakness by carefully timing their requests to read TCP data that contains residual information from previous requests, potentially gaining insights into client IP addresses, HTTP headers, and other network-related metadata. This information can be leveraged for further attacks including session hijacking, fingerprinting, and targeting specific vulnerabilities based on discovered client configurations. The opportunistic nature of the exploit means that successful attacks require minimal privileges but can yield significant intelligence for threat actors.
The vulnerability demonstrates a classic example of memory safety issues in web application servers and aligns with ATT&CK technique T1083 (File and Directory Discovery) and T1592 (Gather Victim Host Information) as attackers can use the leaked information to build more targeted attack strategies. Organizations running affected Tomcat versions face elevated risk of reconnaissance and subsequent exploitation, particularly in environments where sensitive header information or IP address patterns might reveal internal network structures or application configurations. The vulnerability affects the fundamental security model of the web server by creating unintended information flow paths that bypass normal access controls and authorization mechanisms.
Mitigation strategies for this vulnerability require immediate patching to versions 6.0.34 and 7.0.22 or later, which contain the necessary fixes for proper request object handling and memory management. System administrators should also implement network segmentation and monitoring to detect anomalous request patterns that might indicate exploitation attempts. Additional defensive measures include implementing request rate limiting, deploying web application firewalls, and conducting regular security assessments to identify potential information leakage scenarios. The fix addresses the core memory management issue by ensuring proper object cleanup and preventing the reuse of cached request objects with residual data, thereby eliminating the window of opportunity for information disclosure attacks.