CVE-2012-0217 in Solaris
Summary
by MITRE
The x86-64 kernel system-call functionality in Xen 4.1.2 and earlier, as used in Citrix XenServer 6.0.2 and earlier and other products; Oracle Solaris 11 and earlier; illumos before r13724; Joyent SmartOS before 20120614T184600Z; FreeBSD before 9.0-RELEASE-p3; NetBSD 6.0 Beta and earlier; Microsoft Windows Server 2008 R2 and R2 SP1 and Windows 7 Gold and SP1; and possibly other operating systems, when running on an Intel processor, incorrectly uses the sysret path in cases where a certain address is not a canonical address, which allows local users to gain privileges via a crafted application. NOTE: because this issue is due to incorrect use of the Intel specification, it should have been split into separate identifiers; however, there was some value in preserving the original mapping of the multi-codebase coordinated-disclosure effort to a single identifier.
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Analysis
by VulDB Data Team • 01/07/2025
This vulnerability represents a critical flaw in the x86-64 kernel system-call implementation across multiple operating systems and hypervisors, specifically affecting the sysret instruction handling when dealing with non-canonical addresses. The issue stems from improper implementation of the Intel processor specification regarding system call return mechanisms, creating a privilege escalation vector that can be exploited by local malicious applications. The vulnerability affects a wide range of systems including Xen hypervisors, various Unix-like operating systems, and Microsoft Windows platforms, making it particularly concerning for enterprise environments where multiple systems may be simultaneously vulnerable.
The technical flaw occurs when the kernel's system-call handling code incorrectly uses the sysret path for certain address values that do not conform to the canonical address format required by Intel processors. Canonical addresses are specific address ranges that the processor recognizes as valid for memory operations, and when non-canonical addresses are processed through the sysret mechanism, the processor's behavior becomes unpredictable. This misimplementation allows attackers to manipulate the processor state and potentially execute arbitrary code with elevated privileges, effectively bypassing kernel security controls. The vulnerability is particularly dangerous because it leverages the fundamental system call return mechanism that is used extensively throughout the operating system.
The operational impact of CVE-2012-0217 is severe, as local users with minimal privileges can exploit this flaw to escalate their access to kernel-level privileges, potentially leading to complete system compromise. Attackers can craft malicious applications that trigger the vulnerable code path, causing the processor to execute unintended instructions with elevated privileges. This vulnerability affects systems running on Intel processors that implement the x86-64 architecture, which includes virtually all modern server and desktop platforms. The widespread nature of affected products means that organizations using multiple operating systems and virtualization platforms may face simultaneous exposure, complicating mitigation efforts.
Mitigation strategies for this vulnerability require immediate patching of affected systems, as the flaw represents a fundamental security issue in the kernel's system-call handling mechanism. Organizations should prioritize updating their Xen hypervisor installations, operating systems, and related software to versions that properly implement the sysret instruction handling according to the Intel specification. System administrators should also consider implementing additional monitoring for suspicious system call patterns and privilege escalation attempts. The vulnerability aligns with CWE-119, which addresses "Improper Access of Indexable Resource via Symbolic Permissions," and relates to ATT&CK technique T1068, "Exploitation for Privilege Escalation," making it a significant concern for enterprise security teams. Given the nature of the vulnerability, organizations should also review their system configurations to ensure that unnecessary system calls and kernel interfaces are properly restricted, reducing the attack surface for potential exploitation.