CVE-2008-5689 in OpenSolaris
Summary
by MITRE
tun in IP Tunnel in Solaris 10 and OpenSolaris snv_01 through snv_76 allows local users to cause a denial of service (panic) and possibly execute arbitrary code via a crafted SIOCGTUNPARAM IOCTL request, which triggers a NULL pointer dereference.
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Analysis
by VulDB Data Team • 12/25/2025
The vulnerability identified as CVE-2008-5689 represents a critical security flaw within the IP tunneling subsystem of Solaris 10 and OpenSolaris operating systems. This issue affects versions ranging from snv_01 through snv_76, creating a significant risk for systems utilizing the tun driver for network virtualization. The vulnerability stems from improper input validation within the SIOCGTUNPARAM ioctl command handler, which processes requests related to tunnel parameter retrieval. The flaw manifests when a local attacker crafts a malicious ioctl request that triggers a NULL pointer dereference condition within the kernel space, leading to system instability.
The technical implementation of this vulnerability involves the tun driver's handling of the SIOCGTUNPARAM ioctl command, which is designed to retrieve tunnel parameters from the kernel. When a malformed or crafted request is submitted through this interface, the kernel fails to properly validate the input parameters before attempting to dereference pointers that may be NULL. This NULL pointer dereference results in an immediate system panic, causing the operating system to crash and requiring manual reboot. The vulnerability's potential for arbitrary code execution arises from the possibility that the kernel state corruption could be manipulated to achieve privilege escalation, though this requires additional exploitation vectors beyond the basic denial of service condition.
From an operational perspective, this vulnerability presents a severe risk to enterprise networks that rely on Solaris systems for routing and tunneling operations. The local privilege requirement means that an attacker must already have access to the system to exploit this vulnerability, but the potential for privilege escalation makes it particularly dangerous in environments where local access is not strictly controlled. The denial of service impact can disrupt critical network services, while the arbitrary code execution capability could allow attackers to establish persistent backdoors or escalate privileges to root level access. Network administrators should consider this vulnerability as a high-priority concern in systems where Solaris is used for network virtualization or tunneling functions.
Security mitigations for CVE-2008-5689 should focus on immediate patching of affected Solaris versions, as Oracle released security updates specifically addressing this issue. System administrators should also implement additional monitoring to detect unusual ioctl activity patterns that might indicate exploitation attempts. The vulnerability aligns with CWE-476 which describes NULL pointer dereference conditions, and could potentially map to ATT&CK technique T1068 which involves privilege escalation through local exploits. Organizations should consider implementing least privilege principles and restricting local access to systems running affected Solaris versions until patches are properly deployed and validated in their environments.