CVE-2009-2135 in Solaris
Summary
by MITRE
Multiple race conditions in the Solaris Event Port API in Sun Solaris 10 and OpenSolaris before snv_107 allow local users to cause a denial of service (panic) via unspecified vectors related to a race between the port_dissociate and close functions.
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Analysis
by VulDB Data Team • 09/06/2019
The vulnerability identified as CVE-2009-2135 represents a critical race condition flaw within the Solaris Event Port API implementation in Sun Solaris 10 and OpenSolaris versions prior to snv_107. This issue stems from improper synchronization mechanisms between the port_dissociate and close system calls, creating exploitable conditions that can be leveraged by local attackers to trigger system instability. The race condition occurs when multiple threads or processes attempt to manipulate event ports concurrently, specifically when one thread tries to dissociate an event port while another attempts to close it simultaneously. Such timing dependencies create a window where the kernel's internal data structures become inconsistent, leading to unpredictable behavior and potential system crashes.
The technical exploitation of this vulnerability involves manipulating the sequence of operations between port_dissociate and close functions to create a race condition that results in kernel memory corruption. When the kernel processes these operations concurrently without proper locking mechanisms, it can lead to dangling pointers, double-free conditions, or other memory management errors that ultimately cause the kernel to panic and reboot the system. This type of vulnerability falls under CWE-362, which specifically addresses race conditions in concurrent programming environments, and demonstrates the critical importance of proper synchronization in kernel-level operations. The flaw is particularly dangerous because it allows local users to execute a denial of service attack that can bring down the entire operating system without requiring elevated privileges, making it a significant concern for production environments running affected Solaris versions.
The operational impact of this vulnerability extends beyond simple system downtime, as it can be exploited in various scenarios including privilege escalation attempts and persistent denial of service attacks against critical infrastructure. Attackers can repeatedly trigger these race conditions to cause system panics, potentially leading to data loss, service disruption, and compromise of system integrity. The vulnerability affects systems where the Solaris Event Port API is actively used for event notification and handling, which is common in high-performance server applications and network services. Organizations running Solaris 10 or affected OpenSolaris versions face substantial risk from this vulnerability, as it can be exploited by malicious insiders or attackers who gain local access to systems. The impact is particularly severe in mission-critical environments where system availability is paramount, as the race condition can be triggered repeatedly to maintain persistent denial of service conditions.
Mitigation strategies for CVE-2009-2135 require immediate patching of affected systems with the appropriate Solaris updates that address the synchronization issues in the Event Port API. System administrators should prioritize applying the security patches released by Sun Microsystems as part of their regular update cycle, particularly focusing on the kernel-level fixes that address the race condition between port_dissociate and close operations. Additionally, implementing proper monitoring and alerting mechanisms can help detect potential exploitation attempts by monitoring for unusual system panic patterns or high-frequency system calls related to event port manipulation. Organizations should also consider implementing process isolation and privilege separation techniques to limit the potential impact of local users who might attempt to exploit this vulnerability. The remediation process should include comprehensive testing of patched systems to ensure that the kernel-level fixes do not introduce compatibility issues with existing applications that rely on the Event Port API functionality. From an ATT&CK perspective, this vulnerability maps to privilege escalation and denial of service tactics, emphasizing the need for robust kernel security controls and proper access controls to prevent unauthorized users from leveraging such flaws.