CVE-2021-46744

Guest data inference via ciphertext monitoring

Published May 11, 2022 · Updated Sep 16, 2024

Information disclosure in AMD SEV on EPYC processors allows attackers controlling a malicious hypervisor to infer guest data from ciphertext. The hypervisor repeatedly observes ciphertext for specific cryptographic algorithms and correlates value changes over time, exposing patterns in encrypted guest computations. Exploitation requires control of the hypervisor hosting an SEV guest, and the disclosed consequence is inference of data values rather than direct guest-memory reads or modification.

CVSS severity6.5
Medium
EPSS probability0.33%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Information disclosure in AMD SEV on EPYC processors allows attackers controlling a malicious hypervisor to infer guest data from ciphertext. The hypervisor repeatedly observes ciphertext for specific cryptographic algorithms and correlates value changes over time, exposing patterns in encrypted guest computations. Exploitation requires control of the hypervisor hosting an SEV guest, and the disclosed consequence is inference of data values rather than direct guest-memory reads or modification.

The record

CVE
CVE-2021-46744
Published
May 11, 2022
Updated
Sep 16, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-203
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. May 11, 2022CVE publishedPublication date reported by the CVE source.
  2. Sep 16, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

2.1NIST National Vulnerability DatabaseAV:L/AC:L/Au:N/C:P/I:N/A:N
6.5NIST National Vulnerability DatabaseCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-203Observable Discrepancy

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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