A vulnerability in Xen could allow a local attacker on a guest system to gain elevated privileges or cause a denial of service (DoS) condition on a host system.
The vulnerability is due to an array overrun condition that could occur when the High Precision Event Timer (HPET) timer used by the affected software is configured to deliver interrupts in IO-APIC mode. An attacker on a guest system that has the HPET timer configured to deliver interrupts in IO-APIC mode could exploit this vulnerability to cause the hypervisor on the host system to crash, resulting in a DoS condition. In addition, the attacker could have the ability to gain elevated privileges on the targeted system, which could be used to conduct further attacks.
Xen.org has confirmed the vulnerability and released software updates.
To exploit this vulnerability, the attacker must have user-level access to a guest system being hosted by a targeted host system. This access requirement could reduce the likelihood of a successful exploit.
Only x86 systems are affected by this vulnerability. ARM systems are not affected.
Administrators are advised to apply the appropriate updates.
Administrators are advised to allow only trusted users to access local systems.
Administrators are advised to allow only privileged users to access administration or management systems.
Administrators are advised to monitor critical systems.
Xen.org has released a security advisory at the following link: XSA-261
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Cisco Multivendor Vulnerability Alerts respond to vulnerabilities identified in third-party vendors' products. These alerts contain information compiled from diverse sources and provide comprehensive technical descriptions, objective analytical assessments, workarounds and practical safeguards, and links to vendor advisories and patches.