CVE-2010-2068 in HTTP Server
Summary
by MITRE
mod_proxy_http.c in mod_proxy_http in the Apache HTTP Server 2.2.9 through 2.2.15, 2.3.4-alpha, and 2.3.5-alpha on Windows, NetWare, and OS/2, in certain configurations involving proxy worker pools, does not properly detect timeouts, which allows remote attackers to obtain a potentially sensitive response intended for a different client in opportunistic circumstances via a normal HTTP request.
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Analysis
by VulDB Data Team • 02/01/2019
The vulnerability described in CVE-2010-2068 represents a critical security flaw in the Apache HTTP Server's mod_proxy_http module that affects versions between 2.2.9 and 2.2.15, as well as specific alpha versions of 2.3.4 and 2.3.5. This issue specifically manifests on Windows, NetWare, and OS/2 operating systems when the server operates in configurations that utilize proxy worker pools. The core problem lies in the module's inadequate timeout detection mechanisms, which create a window of opportunity for malicious actors to exploit the system's proxy functionality. The vulnerability operates under the CWE-200 principle of information exposure and falls within the ATT&CK technique of T1071.3 for application layer protocol, specifically targeting HTTP proxy communications.
The technical implementation of this flaw stems from how mod_proxy_http handles connection timeouts within its worker pool architecture. When multiple client requests are processed through the same proxy worker threads, the module fails to properly distinguish between different client sessions during timeout scenarios. This creates a scenario where response data intended for one client may be inadvertently delivered to another client who happens to be using the same worker thread at the time of the timeout event. The vulnerability is particularly insidious because it occurs during normal HTTP request processing, making it difficult to detect and exploit through conventional monitoring systems. The flaw exploits the fundamental race condition that occurs when multiple concurrent connections share the same processing resources without proper isolation mechanisms.
The operational impact of CVE-2010-2068 extends beyond simple information disclosure, as the potentially sensitive response data could contain authentication tokens, session identifiers, personal information, or proprietary business data. Attackers can leverage this vulnerability through opportunistic circumstances where they simply need to submit normal HTTP requests to trigger the timeout condition and capture the misdirected responses. The vulnerability affects systems that rely heavily on proxy functionality, particularly those serving as reverse proxies or forward proxies in enterprise environments. Organizations with complex proxy configurations, load balancing setups, or systems that handle sensitive data through proxy workers are particularly at risk. The attack vector requires minimal sophistication and can be automated, making it a significant concern for security administrators who may not even be aware of the vulnerability until exploitation occurs.
Mitigation strategies for this vulnerability should focus on immediate patching of affected Apache installations to versions that contain the necessary timeout detection improvements. Organizations should also implement network segmentation and access controls to limit exposure of vulnerable proxy configurations. Monitoring systems should be enhanced to detect unusual patterns in proxy worker thread usage and response timing anomalies. Security teams should conduct comprehensive audits of all proxy configurations to identify systems running vulnerable versions and ensure proper timeout handling is implemented. The vulnerability demonstrates the importance of proper resource isolation in multi-threaded environments and highlights the need for robust timeout mechanisms in proxy server implementations. Additionally, organizations should consider implementing additional layers of security such as request/response correlation mechanisms and more sophisticated logging to detect potential exploitation attempts. The incident underscores the critical nature of maintaining up-to-date software versions and the importance of thorough testing of security patches in production environments before deployment.