CVE-2010-0419 in KVM
Summary
by MITRE
The x86 emulator in KVM 83, when a guest is configured for Symmetric Multiprocessing (SMP), does not properly restrict writing of segment selectors to segment registers, which might allow guest OS users to cause a denial of service (guest OS crash) or gain privileges on the guest OS by leveraging access to a (1) IO port or (2) MMIO region, and replacing an instruction in between emulator entry and instruction fetch.
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Analysis
by VulDB Data Team • 05/01/2026
The vulnerability identified as CVE-2010-0419 resides within the kernel-based virtual machine implementation of Linux systems, specifically affecting KVM version 83 and earlier. This flaw manifests in the x86 emulator component that handles virtualization of x86 instruction sets when Symmetric Multiprocessing configurations are active. The vulnerability represents a critical security weakness that exploits improper validation mechanisms within the virtualization layer, creating potential attack vectors that could compromise guest operating system integrity.
The technical flaw stems from inadequate restrictions on segment selector writes to segment registers within the KVM x86 emulator during SMP guest configurations. When a guest operating system operates with multiple virtual processors, the emulator fails to properly validate or constrain writes to segment registers, allowing malicious guest users to manipulate these critical processor state elements. This improper access control mechanism enables attackers to inject malicious code or manipulate instruction execution flow within the virtualized environment.
The operational impact of this vulnerability extends beyond simple denial of service conditions to encompass potential privilege escalation scenarios within the guest operating system. Attackers leveraging this weakness can exploit access to IO ports or MMIO regions to replace instructions during the emulator entry and instruction fetch cycle. This timing window creates opportunities for malicious code injection that could escalate privileges within the guest environment, potentially allowing attackers to execute arbitrary code with elevated privileges or cause complete guest OS crashes.
The vulnerability aligns with CWE-119, which addresses improper restriction of operations within a memory buffer, and demonstrates characteristics consistent with privilege escalation vulnerabilities in virtualization platforms. From an ATT&CK framework perspective, this weakness maps to techniques involving privilege escalation and code injection within virtualized environments, specifically targeting the hypervisor's instruction emulation capabilities. The vulnerability represents a fundamental flaw in the virtualization layer's protection mechanisms, where guest users can bypass intended security boundaries through manipulation of processor state elements.
Mitigation strategies should prioritize immediate patching of affected KVM implementations to version 83 or later, where the emulator properly enforces restrictions on segment register writes during SMP configurations. System administrators should also implement monitoring for unusual IO port or MMIO region access patterns that might indicate exploitation attempts. Additional protective measures include disabling unnecessary SMP configurations when not required, implementing strict access controls for virtual machine IO ports, and maintaining comprehensive logging of virtual machine state changes to detect potential exploitation attempts. Organizations should also consider implementing network segmentation and access controls to limit potential attack vectors that could leverage this vulnerability.