CVE-2008-2121 in Solaris
Summary
by MITRE
The TCP implementation in Sun Solaris 8, 9, and 10 allows remote attackers to cause a denial of service (CPU consumption and new connection timeouts) via a TCP SYN flood attack.
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Analysis
by VulDB Data Team • 05/31/2025
The vulnerability described in CVE-2008-2121 represents a critical weakness in the Transmission Control Protocol implementation within Sun Solaris operating systems versions 8, 9, and 10. This flaw specifically targets the TCP synchronization mechanism that is fundamental to establishing reliable network connections. The vulnerability manifests as a denial of service condition that can severely impact system availability and performance by consuming excessive CPU resources while simultaneously causing new connection attempts to time out.
The technical nature of this vulnerability stems from inadequate handling of TCP SYN flood attacks within the Solaris kernel's network stack implementation. When subjected to a SYN flood attack, the system's TCP state machine fails to properly manage the backlog of half-open connections that accumulate during the three-way handshake process. This improper resource management leads to a situation where the system's CPU cycles become consumed with processing these malformed connection requests while legitimate connection attempts are delayed or rejected due to connection timeout issues. The vulnerability operates at the network protocol level and affects the core TCP/IP stack implementation that is essential for all network communications on the affected Solaris systems.
The operational impact of this vulnerability extends beyond simple service disruption to encompass significant performance degradation and availability issues for systems running affected Solaris versions. Attackers can exploit this weakness to consume system resources at an alarming rate, effectively rendering the affected systems unable to process legitimate network traffic. This creates a scenario where even routine network operations become severely impacted, as the system's ability to establish new connections becomes compromised while existing connections may experience delays. The resource exhaustion manifests in both CPU utilization spikes and connection timeout failures, making the system effectively unusable for network-based services.
From a cybersecurity perspective, this vulnerability aligns with common attack patterns identified in the MITRE ATT&CK framework under the 'Resource Exhaustion' technique category, specifically targeting system resources through network-based attacks. The vulnerability also relates to CWE-400, which addresses 'Uncontrolled Resource Consumption' in software systems, and represents a classic example of how network protocol implementations can become attack vectors when proper resource management and attack mitigation mechanisms are not adequately implemented. Organizations running affected Solaris systems face significant risk of operational disruption and potential business impact when this vulnerability is exploited.
Mitigation strategies for CVE-2008-2121 should include immediate deployment of vendor-provided patches and updates from Sun Microsystems to address the TCP implementation flaw. System administrators should also implement network-level protections such as SYN cookies, connection rate limiting, and firewall rules to limit the impact of potential SYN flood attacks. Additionally, monitoring systems should be configured to detect unusual patterns of connection attempts and CPU utilization spikes that may indicate exploitation attempts. The implementation of intrusion detection systems and network monitoring tools can help identify and respond to potential attacks before they cause significant service disruption. Organizations should also consider implementing network segmentation and access control measures to limit the potential impact of successful exploitation attempts.