CVE-2014-3124 in Xen
Summary
by MITRE
The HVMOP_set_mem_type control in Xen 4.1 through 4.4.x allows local guest HVM administrators to cause a denial of service (hypervisor crash) or possibly execute arbitrary code by leveraging a separate qemu-dm vulnerability to trigger invalid page table translations for unspecified memory page types.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 06/19/2021
The vulnerability identified as CVE-2014-3124 resides within the Xen hypervisor's HVMOP_set_mem_type control interface, affecting versions 4.1 through 4.4.x. This issue represents a critical security flaw that demonstrates how seemingly isolated vulnerabilities in hypervisor components can combine to create severe operational risks for virtualized environments. The vulnerability specifically targets the handling of memory type operations within hardware virtual machine (HVM) contexts, where guest administrators with appropriate privileges can manipulate memory page table translations to achieve unintended system behavior.
The technical flaw manifests through an improper validation mechanism in the HVMOP_set_mem_type control operation that fails to adequately verify memory page type specifications. When combined with a separate vulnerability present in qemu-dm, this flaw enables malicious actors to construct invalid page table entries that trigger hypervisor crashes or potentially allow privilege escalation. The vulnerability's impact extends beyond simple denial of service as it can potentially enable arbitrary code execution within the hypervisor context, representing a significant compromise of the virtualization security model. This combination exploits the trust relationship between hypervisor components and guest operating systems, where legitimate administrative operations become vectors for system compromise.
From an operational perspective, this vulnerability creates substantial risk for cloud providers and virtualization environments that host multiple tenants, as local guest administrators can leverage their privileges to either crash the hypervisor or potentially gain elevated system access. The vulnerability's exploitation requires a specific combination of conditions including access to a guest HVM instance and knowledge of the underlying qemu-dm vulnerability, but once exploited, the impact can be severe. The potential for privilege escalation means that what begins as a denial of service attack could evolve into a full system compromise, making this vulnerability particularly dangerous in multi-tenant environments where isolation between guests is critical.
The vulnerability aligns with CWE-122, which addresses improper restriction of operations within a memory buffer, and demonstrates how memory management flaws in hypervisor code can create attack vectors that bypass traditional security boundaries. From an ATT&CK framework perspective, this vulnerability maps to techniques involving privilege escalation and denial of service, specifically targeting the hypervisor layer where such operations can have cascading effects across all virtual machines hosted on the affected system. Organizations using affected Xen versions should prioritize patching and implement monitoring for unusual hypervisor behavior, as the vulnerability's exploitation can be subtle and may not immediately manifest as obvious system crashes. The remediation approach requires updating to patched versions of Xen while also reviewing and hardening the qemu-dm configuration to prevent exploitation of the supporting vulnerability.