CVE-2005-1391 in Pound
Summary
by MITRE
Buffer overflow in the add_port function in APSIS Pound 1.8.2 and earlier allows remote attackers to execute arbitrary code via a long Host HTTP header.
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Analysis
by VulDB Data Team • 06/06/2019
The vulnerability identified as CVE-2005-1391 represents a critical buffer overflow flaw within the APSIS Pound load balancer version 1.8.2 and earlier. This issue resides in the add_port function which processes incoming HTTP requests, specifically targeting the handling of the Host header field. The buffer overflow occurs when the application fails to properly validate the length of the Host header, allowing an attacker to supply an excessively long string that exceeds the allocated buffer space. This fundamental memory management error creates a condition where adjacent memory locations can be overwritten, potentially leading to arbitrary code execution. The vulnerability is particularly dangerous because it operates at the network level, enabling remote attackers to exploit the flaw without requiring local system access or authentication credentials. The attack vector leverages the standard HTTP protocol, making it easily accessible through conventional web traffic manipulation techniques.
The technical implementation of this vulnerability follows established patterns of buffer overflow exploitation as classified under CWE-121, which describes the condition where a program writes data to a buffer without proper bounds checking. In the context of this specific flaw, the add_port function lacks adequate input validation mechanisms to prevent buffer overflows when processing HTTP headers. The Host header, which is a standard component of HTTP requests used to specify the domain name of the server being requested, becomes the attack surface when its length exceeds the predetermined buffer capacity. This creates a scenario where stack-based buffer overflow conditions can be triggered, allowing attackers to overwrite return addresses and execution pointers within the program's memory space. The vulnerability aligns with ATT&CK technique T1190, which covers exploitation of remote services through buffer overflow attacks, making it a prime target for automated exploitation tools and malicious actors seeking to compromise web infrastructure.
The operational impact of CVE-2005-1391 extends beyond simple denial of service conditions, as the remote code execution capability provides attackers with complete system compromise potential. When successfully exploited, the vulnerability allows unauthorized individuals to execute arbitrary commands on the affected Pound load balancer system, potentially gaining full administrative control over the network infrastructure. This compromise can lead to data exfiltration, service disruption, and establishment of persistent access points within the network environment. The vulnerability affects organizations relying on Pound as their load balancing solution, particularly those with internet-facing services that process HTTP traffic. The exploitation process typically involves crafting a malicious HTTP request containing an overly long Host header, which when processed by the vulnerable application triggers the buffer overflow condition. Given that Pound was widely deployed in enterprise environments for traffic distribution and load balancing, the potential impact of this vulnerability was significant across multiple organizations and industries.
Mitigation strategies for CVE-2005-1391 should prioritize immediate patching of affected systems with the vendor-provided security updates that address the buffer overflow condition in the add_port function. Organizations should implement network segmentation and access controls to limit exposure of vulnerable Pound instances to untrusted networks. Input validation mechanisms should be strengthened to enforce maximum length limits on HTTP headers, particularly the Host field, preventing maliciously long values from reaching the vulnerable code path. Network monitoring solutions should be configured to detect and alert on unusually long HTTP headers that may indicate exploitation attempts. Additionally, implementing defense-in-depth measures such as intrusion detection systems, web application firewalls, and regular security assessments can help identify and prevent exploitation attempts. The remediation process should include thorough testing of patched systems to ensure that the vulnerability is fully resolved without introducing new compatibility issues. Organizations should also consider upgrading to more recent versions of Pound or alternative load balancing solutions that have addressed this vulnerability and maintain active security support. Regular vulnerability assessments and security audits should be conducted to identify similar buffer overflow conditions in other network services and applications within the infrastructure.