CVE-2022-24903Network attack vector

Receiver crash via oversized octet-count prefix

Published May 5, 2022 · Updated Apr 23, 2025

Heap buffer overflow in rsyslog before 8.2204.1 allows remote attackers to crash TCP syslog receivers via octet-counted framing. The octet-count parser keeps writing frame-length digits into a heap buffer after the maximum count is exceeded, allowing adjacent heap data to be corrupted. The affected imtcp, imptcp, imhttp, imgssapi, and imdiag modules accept this framing; receivers enable it by default, but senders must select it.

CVSS severity8.1
High
EPSS probability3.93%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Heap buffer overflow in rsyslog before 8.2204.1 allows remote attackers to crash TCP syslog receivers via octet-counted framing. The octet-count parser keeps writing frame-length digits into a heap buffer after the maximum count is exceeded, allowing adjacent heap data to be corrupted. The affected imtcp, imptcp, imhttp, imgssapi, and imdiag modules accept this framing; receivers enable it by default, but senders must select it.

The record

CVE
CVE-2022-24903
Published
May 5, 2022
Updated
Apr 23, 2025
Vendor
rsyslog
Product
rsyslog
Classifications
CWE-118, CWE-120, CWE-1284, T1210
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 5, 2022CVE publishedPublication date reported by the CVE source.
  2. Apr 23, 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=< 8.2204.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

rsyslog · rsyslogversion=< 8.2204.1

Published CVSS scores

6.8NIST NVDAV:N/AC:M/Au:N/C:P/I:P/A:P
8.1GitHub, Inc.CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/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.

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

No observations available

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

Weakness, pattern, technique

CWE-118Incorrect Access of Indexable Resource ('Range Error')
CWE-120Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
CWE-1284Improper Validation of Specified Quantity in Input
T1210Exploitation of Remote Services

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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