Description

IBM PowerVM Hypervisor FW1110.00 through FW1110.20, FW1060.00 through FW1060.71, and FW950.00 through FW950.H2 could allow a local attacker with administrative privileges to decrypt encrypted data due to certain hypervisor calls utilizing less entropy than requested.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "5.3",
  "pubDate": "2026-08-19T21:16:55.570Z",
  "pubdate": "2026-08-19T21:16:55.570Z",
  "executiveSummary": "A cryptographic weakness exists within the IBM PowerVM Hypervisor FW1110.00 through FW1110.20, FW1060.00 through FW1060.71, and FW950.00 through FW950.H2 versions, specifically related to the generation of cryptographic entropy during hypervisor calls.\nThe vulnerability allows a local attacker with administrative privileges to compromise encrypted data by exploiting insufficient entropy utilization.\nThe risk implications involve the potential exposure of sensitive encrypted payloads and cryptographic keys, undermining confidentiality assurances provided by the virtualization boundary.\nExploitation requires administrative privileges within a local context to interact with affected hypervisor interfaces.\nRemediation requires applying the appropriate vendor-supplied firmware updates to resolve the entropy generation flaw in the hypervisor architecture.",
  "technicalDetails": "The vulnerability resides within the IBM PowerVM Hypervisor firmware versions FW1110.00 through FW1110.20, FW1060.00 through FW1060.71, and FW950.00 through FW950.H2.\nThe root cause stems from specific hypervisor calls implementing cryptographic operations that utilize significantly less entropy than requested or expected by security standards.\nThis reduction in randomness drastically limits the keyspace or predictability of generated cryptographic parameters, rendering encryption mechanisms susceptible to cryptanalytic attacks.\nTo exploit this vulnerability, an attacker must already possess administrative privileges locally on the system.\nThe attack flow begins with the privileged local actor initiating specific hypervisor calls designed to invoke the flawed cryptographic routines.\nBecause the underlying routines rely on constrained entropy sources, the resulting cryptographic outputs exhibit predictable patterns or reduced keyspaces.\nThe attacker intercepts or accesses the resulting encrypted data and applies cryptographic analysis or brute-force techniques to exploit the low entropy.\nPost-exploitation impact includes the successful decryption of sensitive data, compromising the cryptographic confidentiality guarantees enforced by the hypervisor layer.\nNo network exposure is explicitly required for initial access, as the attack vector is localized to administrative interfaces capable of issuing hypervisor calls."
}