Vulnerability Status: CVE-2004-0230 (TCP Sequence Number Approximation)

Products

• CA Identity Suite
• CA Identity Governance
• CA Identity Manager
• CA Identity Portal

Issue/Introduction

This article clarifies the security posture of IGA applications regarding CVE-2004-0230. Engineering has validated that IGA applications are not vulnerable to this TCP-based denial-of-service condition due to specific architectural design choices regarding session management and network communication.

CVE-2004-0230

TCP, when using a large Window Size, makes it easier for remote attackers to guess sequence numbers and cause a denial of service (terminate network sessions) to persistent TCP connections by repeatedly injecting a TCP RST packet, especially in protocols that use long-lived connections, such as Border Gateway Protocol (BGP).

Vulnerability Additional Details:

The vulnerable situation arises due to Border Gateway Protocol (BGP) relies on long-lived persistent Transmission Control Protocol (TCP) to maintain persistent unauthenticated network sessions with larger window sizes to function. The ability to predict Initial Sequence Number (ISN)s within these windows can lead to TCP connection hijacking or spoofing.

The primary function of Border Gateway Protocol (BGP) is to exchange routing and reachability information among different autonomous systems on the internet. When a BGP session is disrupted, the BGP application restarts and attempts to re-establish a connection to its peers. This may result in a brief loss of service until the fresh routing tables are created.

Environment

All IGA Products

Resolution

IGA products are not vulnerable to CVE-2004-0230. The architectural design of our client/server communication provides inherent resistance to this vulnerability for the following reasons:

• No Unauthenticated Sessions: IGA client/server communication does not rely on persistent, unauthenticated network sessions. All sessions are authenticated and established through secure handshakes.
• Time-Bound Sessions: IGA utilizes keep-alive mechanisms within authenticated sessions for all subsequent communication. These sessions are time-bound, which prevents the exploitation window required for sequence number guessing.
• Session Isolation: IGA packet communication does not rely on BGP (Border Gateway Protocol) routing tables. Because IGA does not open unauthenticated session windows or rely on long-lived, unauthenticated TCP streams, the possibility of injecting a TCP RST packet to disrupt or hijack the connection is not applicable in an IGA deployment.