CVE-2004-0456 in pavuk
Summary
by MITRE
stack-based buffer overflow in pavuk 0.9pl28 0.9pl27 and possibly other versions allows remote web sites to execute arbitrary code via a long http location header.
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Analysis
by VulDB Data Team • 06/20/2019
The vulnerability identified as CVE-2004-0456 represents a critical stack-based buffer overflow flaw affecting pavuk version 0.9pl28 and 0.9pl27, with potential impact extending to other versions within the software suite. This vulnerability resides in the handling of HTTP response headers, specifically the Location header that web servers use to indicate redirects to clients. The flaw occurs when pavuk processes HTTP responses containing excessively long Location headers, causing the application to overwrite adjacent memory on the stack beyond the allocated buffer boundaries. Such buffer overflow conditions create opportunities for malicious actors to inject and execute arbitrary code on systems running vulnerable versions of pavuk, effectively compromising the confidentiality, integrity, and availability of affected systems.
The technical nature of this vulnerability aligns with CWE-121, which describes stack-based buffer overflow conditions where insufficient bounds checking allows attackers to overwrite stack memory. The flaw operates through a classic buffer overflow attack vector where a remote web server crafts an HTTP response containing an overly long Location header that exceeds the buffer size allocated by pavuk for processing such headers. When the application attempts to store this excessive data in its fixed-size buffer, it overflows into adjacent stack memory locations, potentially corrupting return addresses and other critical program state information. This memory corruption enables attackers to manipulate the program execution flow and inject malicious code that executes with the privileges of the pavuk process, typically running with user-level permissions.
The operational impact of this vulnerability extends beyond simple code execution, as it can enable attackers to gain unauthorized access to systems, escalate privileges, and potentially establish persistent backdoors. The remote nature of the attack means that exploitation does not require local system access, making it particularly dangerous for web crawling applications that process content from untrusted sources. Systems running pavuk for web crawling operations become vulnerable to attacks from malicious web servers that craft specially crafted HTTP responses designed to trigger the buffer overflow. The vulnerability also demonstrates the importance of proper input validation in network applications, as the software fails to implement adequate bounds checking on HTTP header data before processing it. This weakness can be exploited in conjunction with other attack techniques to create more sophisticated compromise scenarios, including the potential for remote code execution in web server contexts where pavuk might be used for automated content retrieval and analysis.
Mitigation strategies for CVE-2004-0456 should prioritize immediate patching of affected pavuk versions to the latest stable releases that contain fixes for the buffer overflow vulnerability. Organizations should implement network monitoring to detect unusual HTTP response patterns that might indicate exploitation attempts, particularly focusing on Location headers that exceed normal length parameters. The principle of least privilege should be enforced by running pavuk with minimal required permissions, limiting the potential impact of successful exploitation. Additionally, implementing web application firewalls and intrusion detection systems can help identify and block malicious HTTP responses designed to trigger the vulnerability. Security teams should also conduct regular vulnerability assessments of their web crawling infrastructure to identify other potentially vulnerable applications that might be susceptible to similar buffer overflow conditions, ensuring comprehensive protection across their attack surface. This vulnerability serves as a reminder of the critical importance of input validation and memory safety in network applications, particularly those that process untrusted data from external sources.