CVE-2017-15590 in Xen
Summary
by MITRE
An issue was discovered in Xen through 4.9.x allowing x86 guest OS users to cause a denial of service (hypervisor crash) or possibly gain privileges because MSI mapping was mishandled.
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 01/04/2023
The vulnerability identified as CVE-2017-15590 represents a critical flaw in the Xen hypervisor affecting versions through 4.9.x, specifically impacting x86 guest operating systems. This issue stems from improper handling of Message Signaled Interrupts (MSI) mapping within the virtualization environment, creating a potential pathway for malicious guest users to exploit the hypervisor's interrupt management mechanisms. The flaw exists at the intersection of virtualization security and interrupt handling, where guest operating systems can manipulate MSI mappings to affect the host hypervisor's stability and security posture.
The technical implementation of this vulnerability involves the mismanagement of MSI interrupt mappings between guest virtual machines and the underlying physical hardware. When guest operating systems attempt to configure or modify MSI vectors, the hypervisor fails to properly validate or enforce access controls on these interrupt mappings. This improper handling creates opportunities for privilege escalation or denial of service conditions, as malicious guest users can manipulate interrupt routing to either crash the hypervisor or gain elevated privileges within the virtualization environment. The vulnerability specifically affects x86 architecture implementations where MSI functionality is utilized for interrupt delivery between virtual machines and hardware devices.
The operational impact of CVE-2017-15590 extends beyond simple denial of service scenarios to encompass potential privilege escalation within virtualized environments. Attackers exploiting this vulnerability can cause hypervisor crashes that disrupt all virtual machines running on the affected system, leading to widespread service disruption. More critically, the flaw may enable malicious guest users to escalate their privileges from guest-level access to host-level privileges, potentially allowing them to compromise the entire virtualization infrastructure. This represents a significant security concern for cloud providers and organizations relying on Xen hypervisors for virtual machine deployment, as it undermines the fundamental security isolation between guest operating systems and the host system.
Mitigation strategies for this vulnerability require immediate patching of affected Xen hypervisor versions to 4.10.0 or later, which includes fixes for the MSI mapping handling issues. Organizations should also implement monitoring for unusual interrupt activity patterns and ensure proper virtual machine isolation through hypervisor configuration hardening. The vulnerability aligns with CWE-122 (Heap Overflow) and CWE-248 (Uncaught Exception) categories, representing improper handling of memory operations and exception conditions in virtualized interrupt management. From an ATT&CK framework perspective, this vulnerability maps to techniques involving privilege escalation and denial of service, specifically targeting the hypervisor layer where adversaries can manipulate system resources to gain unauthorized access or disrupt services. System administrators should conduct comprehensive vulnerability assessments of their virtualization environments and implement network segmentation to limit the potential impact of exploitation.