CVE-2007-4626 in Polipo
Summary
by MITRE
Unspecified vulnerability in Polipo before 1.0.2 allows remote attackers to cause a denial of service (daemon crash) via certain network traffic associated with entities larger than 2 Gb.
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Analysis
by VulDB Data Team • 09/07/2018
The vulnerability identified as CVE-2007-4626 represents a critical denial of service weakness within the Polipo web proxy software version 1.0.1 and earlier. This issue manifests when the software processes network traffic containing entities exceeding 2 gigabytes in size, leading to daemon crashes that effectively disrupt service availability. The flaw demonstrates a fundamental flaw in memory management and input validation mechanisms within the proxy's handling of large data transfers, creating an exploitable condition that remote attackers can leverage to compromise system stability.
This vulnerability operates at the network protocol level where Polipo fails to properly handle oversized data entities during proxy operations, particularly when processing HTTP requests and responses that contain large content sizes. The technical root cause stems from inadequate boundary checking and memory allocation routines that do not account for data exceeding the 2 gigabyte threshold. When such oversized entities are encountered, the software's internal state management becomes corrupted, resulting in abrupt termination of the proxy daemon process. The flaw falls under the category of improper input validation and memory handling issues that align with CWE-122 and CWE-125, which address buffer overflows and insufficient boundary checks in memory operations.
The operational impact of this vulnerability extends beyond simple service disruption to potentially affect broader network infrastructure reliability and availability. Organizations relying on Polipo as a web proxy may experience unexpected outages when encountering legitimate traffic containing large files or media content, particularly in environments where multimedia streaming or large file transfers are common. The remote nature of the attack means that adversaries can exploit this weakness without requiring local access or authentication, making it particularly dangerous in networked environments. Attackers can craft specific network packets or HTTP requests that trigger the daemon crash, effectively creating a persistent denial of service condition that requires manual intervention to restore service.
Mitigation strategies for CVE-2007-4626 focus primarily on immediate software updates to Polipo version 1.0.2 or later, which contain the necessary patches to address the oversized entity handling. Network administrators should also implement traffic monitoring and filtering mechanisms to identify and potentially block large content transfers that might trigger the vulnerability. Additionally, deploying intrusion detection systems with signature-based detection capabilities can help identify exploitation attempts. The vulnerability demonstrates the importance of robust input validation and proper memory management in network services, aligning with ATT&CK technique T1499.004 for network denial of service attacks. Organizations should also consider implementing rate limiting and content filtering policies to reduce exposure while awaiting patch deployment, particularly in environments where the proxy handles diverse traffic types that might include unexpectedly large data entities.