CVE-2010-2791 in HTTP Server
Summary
by MITRE
mod_proxy in httpd in Apache HTTP Server 2.2.9, when running on Unix, does not close the backend connection if a timeout occurs when reading a response from a persistent connection, which allows remote attackers to obtain a potentially sensitive response intended for a different client in opportunistic circumstances via a normal HTTP request. NOTE: this is the same issue as CVE-2010-2068, but for a different OS and set of affected versions.
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Analysis
by VulDB Data Team • 02/01/2019
The vulnerability described in CVE-2010-2791 represents a critical security flaw in the Apache HTTP Server's mod_proxy module that specifically affects version 2.2.9 running on Unix operating systems. This issue stems from improper connection management within the proxy module's handling of persistent connections, creating a potential for cross-client data leakage that could expose sensitive information intended for other users. The flaw manifests when the server encounters a timeout while reading responses from backend servers, failing to properly terminate the connection and leaving it in a state where subsequent requests might inadvertently receive responses meant for different clients.
The technical root cause of this vulnerability lies in the mod_proxy module's failure to properly close backend connections when timeouts occur during response reading from persistent connections. This behavior creates a race condition where connection state information remains in memory or connection pools, allowing subsequent HTTP requests to potentially receive cached or improperly routed responses. The vulnerability is classified under CWE-129 as an improper input validation issue, specifically related to inadequate handling of connection lifecycle management in proxy configurations. When a timeout occurs, the module should terminate the backend connection immediately to prevent any data leakage, but instead maintains the connection in an inconsistent state.
The operational impact of this vulnerability is significant as it enables remote attackers to potentially access sensitive data that should be isolated to specific clients. This cross-client information leakage occurs under opportunistic circumstances, meaning that attackers can exploit the vulnerability when the server is under load or when connection timing aligns favorably with their attack window. The vulnerability affects environments using Apache HTTP Server with mod_proxy configured for persistent connections, particularly common in reverse proxy setups, load balancing configurations, and web application gateways where multiple clients connect to the same backend services. Attackers can leverage this weakness to obtain potentially sensitive responses that were intended for other users, creating unauthorized data access scenarios that could compromise user privacy and system integrity.
Organizations should implement immediate mitigations including upgrading to patched versions of Apache HTTP Server, specifically versions 2.2.15 and later which contain the necessary fixes for this connection management issue. Additionally, administrators should consider disabling persistent connections for proxy configurations when sensitive data is involved, or implementing additional connection monitoring and cleanup mechanisms. The vulnerability aligns with ATT&CK technique T1071.004 for application layer protocol, specifically targeting web protocols and proxy services. Security teams should also implement network monitoring to detect anomalous connection patterns that might indicate exploitation attempts, and consider deploying intrusion detection systems that can identify unusual proxy behavior patterns. Organizations using mod_proxy should conduct thorough configuration reviews to ensure proper connection handling and implement automated connection cleanup processes to prevent similar issues from occurring in other components of their infrastructure.