CVE-1999-0908 in Solaris
Summary
by MITRE
Denial of service in Solaris TCP streams driver via a malicious connection that causes the server to panic as a result of recursive calls to mutex_enter.
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Analysis
by VulDB Data Team • 12/27/2024
The vulnerability described in CVE-1999-0908 represents a critical denial of service flaw within the Solaris operating system's TCP streams driver implementation. This issue manifests when a malicious client establishes a specific type of connection that triggers recursive calls to the mutex_enter function, ultimately causing the target server to panic and become unavailable to legitimate users. The vulnerability resides in the kernel-level networking stack where the TCP streams driver fails to properly handle certain connection sequences that lead to infinite recursion in synchronization primitives. This type of flaw falls under the category of resource exhaustion attacks that leverage system-level implementation weaknesses rather than external network vulnerabilities.
The technical mechanism behind this vulnerability involves the exploitation of a race condition or improper state management within the TCP streams driver's mutex handling code. When a malicious connection is established with specific parameters, the driver's connection processing logic enters a recursive loop where mutex_enter calls itself repeatedly without proper exit conditions. This recursive behavior causes the kernel to consume excessive CPU resources and eventually leads to system panic as the kernel's memory management and scheduling mechanisms become overwhelmed by the uncontrolled recursion. The flaw demonstrates poor defensive programming practices where the system fails to implement proper recursion depth checking or termination conditions for critical synchronization operations. According to CWE classification, this vulnerability maps to CWE-121 which describes stack-based buffer overflow conditions, though the specific manifestation here involves recursive mutex calls rather than traditional buffer overflows.
The operational impact of CVE-1999-0908 is severe as it enables remote attackers to cause complete system unavailability without requiring authentication or elevated privileges. Any system running Solaris with the affected TCP streams driver becomes vulnerable to this attack, making it particularly dangerous in production environments where network services are critical. The panic condition results in immediate system crash and requires manual intervention to restore normal operation, potentially causing extended downtime for services hosted on the affected systems. This vulnerability directly impacts the availability aspect of the CIA triad and can be classified under the ATT&CK technique T1499.1 for network denial of service attacks. The attack vector is particularly concerning as it can be executed over standard network connections without requiring any special access rights, making it an attractive target for attackers seeking to disrupt services.
Mitigation strategies for this vulnerability should focus on both immediate system hardening and long-term architectural improvements. System administrators should ensure that all Solaris systems are updated with the latest security patches from Sun Microsystems that address this specific recursion issue in the TCP streams driver. The implementation of connection rate limiting and proper timeout mechanisms can help reduce the impact of such attacks by preventing malicious connections from consuming excessive system resources. Network segmentation and firewall rules can be configured to limit exposure to potentially malicious traffic while monitoring for unusual connection patterns that might indicate exploitation attempts. Additionally, implementing proper kernel debugging and monitoring tools can help detect early signs of recursive call patterns that might lead to system panic. Organizations should also consider implementing intrusion detection systems that can identify and alert on anomalous network behavior associated with this specific attack pattern, as the vulnerability can be detected through network traffic analysis and system log monitoring. The vulnerability highlights the importance of proper kernel-level defensive programming practices and the need for comprehensive testing of synchronization primitives under stress conditions to prevent similar recursion-based failures in the future.