CVE-2022-3821

Local denial of service via format_timespan overflow

Published Nov 8, 2022 · Updated May 2, 2025

An off-by-one error in systemd before v252-rc1 allows local users to cause a denial of service via crafted time and accuracy values. The format_timespan() function in time-util.c mishandles these inputs and overruns its output buffer by one byte. A low-privilege local user must reach code that supplies the values; exploitation can interrupt systemd operation without providing confidentiality or integrity impact.

CVSS severity5.5
Medium
EPSS probability0.42%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

An off-by-one error in systemd before v252-rc1 allows local users to cause a denial of service via crafted time and accuracy values. The format_timespan() function in time-util.c mishandles these inputs and overruns its output buffer by one byte. A low-privilege local user must reach code that supplies the values; exploitation can interrupt systemd operation without providing confidentiality or integrity impact.

The record

CVE
CVE-2022-3821
Published
Nov 8, 2022
Updated
May 2, 2025
Vendor
systemd
Product
systemd
Classifications
CWE-193, T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Nov 8, 2022CVE publishedPublication date reported by the CVE source.
  2. May 2, 2025Record 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 systemd v252-rc1

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

systemd · systemdversion=Fixed in systemd v252-rc1

Published CVSS scores

5.5CISA ADPCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-193Off-by-one Error
T1499Endpoint Denial of Service

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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