CVE-2004-0641 in Speedtouch
Summary
by MITRE
thomson speedtouch 510 adsl router with firmware gv8baa3.270 and possibly earlier versions generates predictable tcp initial sequence numbers (isns) which allows remote attackers to spoof or hijack tcp connections.
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Analysis
by VulDB Data Team • 12/24/2024
The CVE-2004-0641 vulnerability affects the thomson speedtouch 510 adsl router running firmware version gv8baa3.270 and potentially earlier versions, presenting a critical security flaw in network communication protocols. This vulnerability stems from the router's implementation of the Transmission Control Protocol which generates predictable initial sequence numbers, creating a fundamental weakness in connection security that can be exploited by remote attackers.
The technical flaw resides in the router's TCP stack implementation where the initial sequence number generation algorithm lacks sufficient entropy and randomness. This predictable sequence number generation creates a scenario where an attacker can accurately guess the next sequence number in a TCP connection, enabling them to perform session hijacking attacks. The vulnerability specifically impacts the TCP three-way handshake process where the router's predictable ISN generation makes it possible for malicious actors to insert themselves into established connections without proper authentication.
This vulnerability has significant operational impact on affected networks as it allows remote attackers to completely compromise TCP connections without requiring any local access or sophisticated attack techniques. The predictability of sequence numbers means that an attacker can monitor network traffic and use the predictable pattern to inject malicious data, redirect connections, or perform man-in-the-middle attacks. The vulnerability affects any TCP-based services running through the router including web applications, email servers, and other network protocols that rely on TCP for reliable communication.
The attack surface extends beyond simple connection hijacking to encompass broader network compromise opportunities. According to ATT&CK framework, this vulnerability maps to techniques involving network sniffing and connection hijacking, specifically targeting the T1046 Network Service Scanning and T1566 Phishing with Malicious Attachments categories. The predictable ISN generation also aligns with CWE-330 Use of Insufficiently Random Values, which classifies this as a weakness in randomness and entropy generation. Organizations using affected routers face potential data breaches, unauthorized access to sensitive systems, and complete network compromise if attackers successfully exploit this vulnerability.
Mitigation strategies include immediate firmware updates from the vendor to address the predictable sequence number generation issue, network segmentation to limit exposure, implementation of TCP sequence number randomization at the network level, and deployment of intrusion detection systems to monitor for suspicious TCP traffic patterns. Additionally, organizations should consider implementing network access controls and monitoring for unusual connection behaviors that might indicate exploitation attempts. The vulnerability underscores the importance of proper entropy implementation in network security protocols and highlights the critical need for regular firmware updates to address known security flaws.