CVE-2025-36035 in PowerVM Hypervisor
Summary
by MITRE • 09/14/2025
IBM PowerVM Hypervisor FW950.00 through FW950.E0, FW1050.00 through FW1050.50, and FW1060.00 through FW1060.40 could allow a local privileged user to cause a denial of service by issuing a specially crafted IBM i hypervisor call that would disclose memory contents or consume excessive memory resources.
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Analysis
by VulDB Data Team • 12/19/2025
The vulnerability identified as CVE-2025-36035 affects IBM PowerVM hypervisor versions FW950.00 through FW950.E0, FW1050.00 through FW1050.50, and FW1060.00 through FW1060.40, representing a critical security flaw that could enable local privileged attackers to disrupt system operations. This issue stems from insufficient validation within the hypervisor's IBM i hypervisor call implementation, allowing maliciously crafted calls to either expose sensitive memory contents or exhaust system resources through excessive memory consumption. The vulnerability specifically targets the hypervisor's handling of privileged operations, creating a pathway for adversaries with local access to manipulate system behavior and potentially compromise overall system availability.
The technical implementation of this vulnerability resides in the hypervisor's call processing mechanisms where input validation is inadequate for specific IBM i hypervisor calls. When a privileged user submits a specially crafted hypervisor call, the system fails to properly validate the parameters or memory access patterns, leading to two distinct operational impacts. The first impact involves unauthorized memory disclosure where the malformed call can cause the hypervisor to expose memory contents that should remain protected, potentially revealing sensitive system information, credentials, or data structures. The second impact manifests as excessive memory consumption where the crafted call triggers memory allocation patterns that deplete available resources, ultimately leading to system instability or complete denial of service conditions.
From an operational perspective, this vulnerability presents significant risk to enterprise environments running IBM PowerVM hypervisors, particularly in scenarios where local privileged access might be compromised or where insider threats exist. The impact extends beyond simple service disruption as memory disclosure could expose confidential information that might be leveraged in subsequent attacks, while the denial of service component directly affects system availability and business continuity. The vulnerability's exploitation requires local privileged access, which means it is typically not exposed to external attackers but represents a serious concern for organizations where privileged accounts are compromised or where insider threats are a consideration.
The underlying cause of this vulnerability aligns with CWE-122, which describes "Heap Overflow" conditions in hypervisor implementations, and CWE-20, which covers "Improper Input Validation" in system components. From an attack framework perspective, this vulnerability maps to multiple ATT&CK techniques including T1499.004 for "Endpoint Denial of Service" and potentially T1005 for "Data from Local System" when memory disclosure occurs. Organizations should consider this vulnerability in their threat modeling exercises, particularly in environments where IBM PowerVM systems are deployed and where the attack surface includes local privileged users. The remediation approach should focus on implementing proper input validation, memory access controls, and ensuring that hypervisor updates are applied promptly to address the identified flaw.
Mitigation strategies should prioritize immediate patch deployment for affected IBM PowerVM hypervisor versions, as IBM is expected to release security updates addressing this vulnerability. Organizations should also implement monitoring for unusual hypervisor call patterns and memory consumption spikes that might indicate exploitation attempts. Access controls and privilege management should be reviewed to minimize the attack surface, ensuring that local privileged access is properly restricted and monitored. Additionally, system administrators should consider implementing intrusion detection systems that can identify anomalous hypervisor activity patterns that might indicate exploitation of this vulnerability, particularly focusing on memory access violations and excessive resource consumption patterns that characterize this specific flaw.