CVE-2021-4122

Persistent plaintext exposure via unauthenticated reencryption metadata

Published Aug 24, 2022 · Updated Aug 3, 2024

Metadata authentication failure in cryptsetup 2.2.0 through 2.3.6 and 2.4.0 through 2.4.2 allows physically proximate attackers to decrypt LUKS2 data. Crash recovery accepts attacker-modified reencryption metadata without a key-derived digest and rewrites part of the device as plaintext after a valid activation. Exploitation requires repeated physical access: first to alter the header and later to retrieve or modify the exposed plaintext.

CVSS severity5.9
Medium
EPSS probability0.31%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Metadata authentication failure in cryptsetup 2.2.0 through 2.3.6 and 2.4.0 through 2.4.2 allows physically proximate attackers to decrypt LUKS2 data. Crash recovery accepts attacker-modified reencryption metadata without a key-derived digest and rewrites part of the device as plaintext after a valid activation. Exploitation requires repeated physical access: first to alter the header and later to retrieve or modify the exposed plaintext.

The record

CVE
CVE-2021-4122
Published
Aug 24, 2022
Updated
Aug 3, 2024
Vendor
Cryptsetup
Product
cryptsetup
Classifications
CWE-345, CWE-349, T1565
Attack vector
physical
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 24, 2022CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 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?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=Fixed in cryptsetup 2.4.3, cryptsetup 2.3.7

What conditions does exploitation require?

Attack vectorphysical
Required privilegesunauthenticated

What is affected?

Cryptsetup · cryptsetupversion=Fixed in cryptsetup 2.4.3, cryptsetup 2.3.7

Published CVSS scores

4.3National Vulnerability DatabaseCVSS:3.1/AV:P/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N
5.9Red HatCVSS:3.1/AV:P/AC:L/PR:N/UI:R/S:U/C:H/I:H/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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorphysical
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-345Insufficient Verification of Data Authenticity
CWE-349Acceptance of Extraneous Untrusted Data With Trusted Data
T1565Data Manipulation

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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