CVE-2023-28625Network attack vector

Service crash via NULL cookie dereference

Published Apr 3, 2023 · Updated Feb 13, 2025

NULL pointer dereference in OpenIDC mod_auth_openidc 2.0.0 through 2.4.13.1 allows remote attackers to crash Apache via a crafted cookie. The oidc_strip_cookies function advances through cookie data but fails to stop when an empty Cookie header leaves its pointer NULL, then dereferences it. Exploitation requires OIDCStripCookies to be enabled; a request reaching Apache can terminate the server process, affecting availability without reported data access or modification.

CVSS severity7.5
High
EPSS probability1.33%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

NULL pointer dereference in OpenIDC mod_auth_openidc 2.0.0 through 2.4.13.1 allows remote attackers to crash Apache via a crafted cookie. The oidc_strip_cookies function advances through cookie data but fails to stop when an empty Cookie header leaves its pointer NULL, then dereferences it. Exploitation requires OIDCStripCookies to be enabled; a request reaching Apache can terminate the server process, affecting availability without reported data access or modification.

The record

CVE
CVE-2023-28625
Published
Apr 3, 2023
Updated
Feb 13, 2025
Vendor
OpenIDC
Product
mod_auth_openidc
Classifications
CWE-476, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 3, 2023CVE publishedPublication date reported by the CVE source.
  2. Feb 13, 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=>= 2.0.0, < 2.4.13.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

OpenIDC · mod_auth_openidcversion=>= 2.0.0, < 2.4.13.2

Published CVSS scores

7.5GitHub, Inc. CNACVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
5.3GitHub Security AdvisoryCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

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-476NULL Pointer Dereference
T1499.004Application or System Exploitation

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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