CVE-2014-1894 in Xen
Summary
by MITRE
Multiple integer overflows in unspecified suboperations in the flask hypercall in Xen 3.2.x and earlier, when XSM is enabled, allow local users to cause a denial of service (processor fault) via unspecified vectors, a different vulnerability than CVE-2014-1891, CVE-2014-1892, and CVE-2014-1893.
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Analysis
by VulDB Data Team • 05/09/2026
The vulnerability identified as CVE-2014-1894 represents a critical integer overflow condition within the flask hypercall implementation of the Xen hypervisor version 3.2.x and earlier. This flaw specifically manifests in unspecified suboperations within the flask hypercall mechanism, which serves as a crucial security framework for access control and privilege management within the virtualized environment. The vulnerability becomes particularly significant when the Xen Security Module (XSM) is enabled, as this module provides mandatory access controls that govern how virtual machines interact with system resources. The integer overflows occur at the kernel level within hypervisor operations, creating a potential pathway for malicious actors to exploit the system's memory management and execution flow.
The technical exploitation of this vulnerability involves leveraging integer overflow conditions that can lead to memory corruption within the hypervisor's operational context. When the flask hypercall processes certain input parameters, the integer arithmetic operations exceed their maximum representable values, causing unexpected behavior in the system's memory layout and execution flow. These overflows can result in the creation of invalid memory pointers or corrupted data structures that, when processed by the hypervisor's kernel routines, trigger processor faults and system instability. The vulnerability is distinct from other related issues such as CVE-2014-1891, CVE-2014-1892, and CVE-2014-1893, which indicates that this represents a unique code path within the hypercall implementation that requires specific conditions to be exploited successfully.
The operational impact of this vulnerability extends beyond simple denial of service scenarios, as it represents a fundamental weakness in the hypervisor's security architecture. Local users with access to the virtualized environment can potentially cause system crashes or processor faults that may result in complete system instability and service disruption. The vulnerability's exploitation can lead to cascading failures within the virtualized infrastructure, affecting multiple virtual machines running on the same host system. This type of flaw directly violates the principle of isolation that virtualization environments are designed to maintain, as successful exploitation can potentially allow privilege escalation or information disclosure. The integer overflow conditions create a pathway for attackers to manipulate the hypervisor's internal state, which could be leveraged to achieve more sophisticated attacks against the underlying system.
Mitigation strategies for CVE-2014-1894 should prioritize immediate patching of affected Xen hypervisor versions to address the integer overflow conditions in the flask hypercall implementation. Organizations should implement comprehensive monitoring for unusual system behavior or processor faults that might indicate exploitation attempts. The security community should consider implementing additional access controls and privilege restrictions to limit the potential impact of local users who might attempt to exploit this vulnerability. This vulnerability aligns with CWE-190, which describes integer overflow conditions, and relates to ATT&CK techniques involving privilege escalation and system exploitation. Regular security assessments and vulnerability scanning should be conducted to identify systems running vulnerable versions of Xen, with immediate remediation prioritized for environments where the risk of exploitation is highest. The remediation process should include thorough testing of patched systems to ensure that the vulnerability has been fully addressed without introducing new stability issues in the virtualized environment.