CVE-2009-4226 in OpenSolaris
Summary
by MITRE
Race condition in the IP module in the kernel in Sun OpenSolaris snv_106 through snv_124 allows remote attackers to cause a denial of service (NULL pointer dereference and panic) via unspecified vectors related to the (1) tcp_do_getsockname or (2) tcp_do_getpeername function.
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Analysis
by VulDB Data Team • 01/25/2019
The vulnerability identified as CVE-2009-4226 represents a critical race condition within the Internet Protocol module of Sun OpenSolaris kernel versions ranging from snv_106 through snv_124. This flaw exists in the kernel's handling of TCP socket operations and specifically affects the tcp_do_getsockname and tcp_do_getpeername functions. The race condition occurs when multiple threads or processes simultaneously access shared kernel data structures without proper synchronization mechanisms, creating a window where the system can transition into an inconsistent state. Such conditions are particularly dangerous in kernel space as they can lead to unpredictable behavior and system instability. The vulnerability classifies under CWE-362 which specifically addresses race conditions in concurrent programming environments where multiple threads access shared resources without adequate protection mechanisms. The potential for exploitation by remote attackers makes this a significant concern for networked systems that rely on OpenSolaris kernel functionality.
The technical implementation of this vulnerability stems from improper synchronization during socket state transitions within the TCP protocol stack. When the tcp_do_getsockname or tcp_do_getpeername functions are invoked concurrently, the kernel fails to properly lock or serialize access to critical socket data structures. This allows an attacker to manipulate the timing of operations such that a socket structure becomes temporarily invalid or in an inconsistent state. The NULL pointer dereference that results from this condition occurs when the kernel attempts to access memory locations that have been freed or never properly initialized due to the race window. The panic condition represents the kernel's response to this critical error, causing an immediate system crash and resulting in denial of service for all network services running on the affected system. This type of kernel-level panic represents a fundamental failure in system stability and can be exploited to create sustained denial of service attacks against OpenSolaris systems.
The operational impact of CVE-2009-4226 extends beyond simple service disruption to encompass complete system compromise and availability degradation. Remote attackers can leverage this vulnerability to systematically crash systems without requiring any special privileges or authentication credentials, making it particularly dangerous in multi-tenant environments or systems handling critical network traffic. The vulnerability affects the core networking stack, meaning that any service relying on TCP communications could be impacted, including web servers, database systems, email services, and file transfer protocols. The timing requirements for exploitation suggest that attackers may need to carefully coordinate their attacks to maximize the probability of hitting the race condition window, but the fundamental nature of the flaw means that any system running the affected OpenSolaris versions remains vulnerable. This vulnerability directly maps to ATT&CK technique T1499.004 which covers network denial of service attacks, and more broadly to T1499 which encompasses various denial of service tactics that can be used to disrupt system availability.
Mitigation strategies for CVE-2009-4226 primarily focus on system updates and operational security measures. The most effective remediation involves upgrading to Sun OpenSolaris versions that have patched this race condition, specifically those beyond the affected snv_106 through snv_124 range. System administrators should implement immediate patch management procedures to ensure all affected systems receive the appropriate kernel updates. Network segmentation and intrusion detection systems can help monitor for exploitation attempts, though the nature of the vulnerability makes detection challenging since it occurs at the kernel level. Additionally, implementing proper access controls and limiting network exposure of systems running affected OpenSolaris versions can reduce the attack surface. The vulnerability highlights the importance of proper kernel synchronization mechanisms and proper handling of concurrent access to shared resources in operating system design. Organizations should also consider implementing redundant systems and failover mechanisms to maintain service availability in case of exploitation attempts. The incident underscores the necessity of thorough testing of concurrent programming models and proper validation of race condition protections in kernel-level code, particularly in high-availability environments where system stability is paramount.