CVE-2023-31439Public exploit

Sealed log forgery via one-way epoch validation

Published Jun 13, 2023 · Updated Aug 2, 2024

Improper journal integrity verification in systemd 198 through 254 allows attackers to forge sealed past log entries undetected. journalctl --verify rejects newer entries sealed with an older epoch key but fails to reject older entries sealed with a newer key, allowing the current key to authenticate backdated modifications. Exploitation requires control of the host and its current sealing key; the result is undetected alteration of historical journal evidence, not code execution or service interruption.

CVSS severity5.3
Medium
EPSS probability0.35%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper journal integrity verification in systemd 198 through 254 allows attackers to forge sealed past log entries undetected. journalctl --verify rejects newer entries sealed with an older epoch key but fails to reject older entries sealed with a newer key, allowing the current key to authenticate backdated modifications. Exploitation requires control of the host and its current sealing key; the result is undetected alteration of historical journal evidence, not code execution or service interruption.

The record

CVE
CVE-2023-31439
Published
Jun 13, 2023
Updated
Aug 2, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-354, T1070.002
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Jun 13, 2023CVE publishedPublication date reported by the CVE source.
  2. Aug 2, 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

5.3NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
2.3SUSECVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:L/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 exploitPublished

Weakness, pattern, technique

CWE-354Improper Validation of Integrity Check Value
T1070.002Clear Linux or Mac System Logs

Public exploit references

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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