CVE-2007-5481 in DCC
Summary
by MITRE
Distributed Checksum Clearinghouse (DCC) 1.3.65 allows remote attackers to cause a denial of service (crash) via a "SOCKS flood."
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Analysis
by VulDB Data Team • 09/10/2018
The Distributed Checksum Clearinghouse DCC version 1.3.65 contains a critical vulnerability that enables remote attackers to induce a denial of service condition through a specific network attack pattern known as SOCKS flood. This vulnerability represents a significant security weakness in the email spam filtering system that was widely deployed in email infrastructure environments. The DCC system operates as a distributed network of checksum databases designed to identify and block spam messages by analyzing message content patterns and comparing them against known spam signatures. When exploited, this vulnerability can cause the targeted DCC server to crash and become unavailable, disrupting legitimate email processing and potentially affecting downstream email services that depend on its functionality.
The technical flaw underlying CVE-2007-5481 stems from inadequate input validation and connection handling mechanisms within the DCC software's SOCKS proxy implementation. A SOCKS flood attack involves sending a large volume of malformed or excessive SOCKS protocol requests to the vulnerable DCC server, overwhelming its processing capabilities and causing resource exhaustion. This attack pattern specifically targets the server's ability to handle concurrent connections and process incoming network requests through the SOCKS proxy interface. The vulnerability manifests when the DCC server fails to properly validate incoming SOCKS protocol data, leading to memory corruption or stack overflow conditions that ultimately result in application crash and service termination.
The operational impact of this vulnerability extends beyond simple service disruption to potentially compromise email infrastructure reliability and availability. Organizations relying on DCC for spam filtering may experience significant email delivery delays or complete service outages when attackers exploit this weakness. The vulnerability affects the broader email security ecosystem since DCC servers often serve as critical components in anti-spam architectures, and their compromise can lead to increased spam volume reaching end users. Network administrators face the challenge of maintaining email service availability while addressing this vulnerability, as the attack can be executed remotely without requiring authentication or specialized access to the target system.
Mitigation strategies for CVE-2007-5481 should focus on implementing network-level protections and software updates to address the underlying SOCKS handling flaws. Organizations should deploy firewall rules to restrict access to DCC SOCKS proxy ports and implement rate limiting to prevent excessive connection attempts. The most effective long-term solution involves upgrading to patched versions of DCC software that properly validate incoming SOCKS protocol data and implement robust connection handling mechanisms. Security teams should also consider implementing intrusion detection systems that can identify and alert on suspicious SOCKS flood patterns, enabling rapid response to potential exploitation attempts. This vulnerability aligns with CWE-129, which addresses improper validation of input boundaries, and can be classified under ATT&CK technique T1499 for network denial of service attacks, demonstrating how this weakness fits into broader cybersecurity threat frameworks.
The vulnerability demonstrates the importance of proper input validation in network services and highlights the risks associated with proxy implementations in security infrastructure software. Legacy DCC installations remain particularly vulnerable as they may not receive security updates, emphasizing the need for regular software maintenance and security assessments. Organizations should conduct comprehensive vulnerability assessments to identify all instances of DCC software in their infrastructure and ensure proper patch management protocols are in place to prevent exploitation of similar weaknesses in other network security tools.