CVE-2022-23556Network attack vector

IP address spoofing via trusted forwarding headers

Published Dec 22, 2022 · Updated Apr 15, 2025

Insufficient data-authenticity checks in CodeIgniter 4 before 4.2.11 allow remote attackers to spoof client IP addresses through proxy headers. RequestTrait::getIPAddress accepts the first syntactically valid value from several client-controlled forwarding headers whenever REMOTE_ADDR matches a configured proxy, rather than binding that proxy to one trusted header. The flaw is reachable only behind a trusted reverse proxy when application logic relies on the returned address, allowing IP-based logging or access decisions to be falsified.

CVSS severity7.5
High
EPSS probability0.37%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Insufficient data-authenticity checks in CodeIgniter 4 before 4.2.11 allow remote attackers to spoof client IP addresses through proxy headers. RequestTrait::getIPAddress accepts the first syntactically valid value from several client-controlled forwarding headers whenever REMOTE_ADDR matches a configured proxy, rather than binding that proxy to one trusted header. The flaw is reachable only behind a trusted reverse proxy when application logic relies on the returned address, allowing IP-based logging or access decisions to be falsified.

The record

CVE
CVE-2022-23556
Published
Dec 22, 2022
Updated
Apr 15, 2025
Vendor
CodeIgniter Foundation
Product
CodeIgniter 4
Classifications
CWE-345
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Dec 22, 2022CVE publishedPublication date reported by the CVE source.
  2. Apr 15, 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=< 4.2.11

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

CodeIgniter Foundation · CodeIgniter 4version=< 4.2.11

Published CVSS scores

7.0GitHubCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:L
7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/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 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-345Insufficient Verification of Data Authenticity

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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