CVE-2023-45367Public exploitNetwork attack vector

Authenticated denial of service via unbounded row insertion

Published Oct 9, 2023 · Updated Sep 19, 2024

Denial of service in the MediaWiki CheckUser extension allows remote authenticated users to interrupt service through a crafted REST request. The client-hints handler accepts attacker-controlled brands and fullVersionList arrays, and toDatabaseRows inserts every member into cu_useragent_clienthints without a bound. The route requires a valid revision context and low-privileged access; Wikimedia states that the affected code existed only on master and wmf branches, not in a released version.

CVSS severity6.5
Medium
EPSS probability0.54%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in the MediaWiki CheckUser extension allows remote authenticated users to interrupt service through a crafted REST request. The client-hints handler accepts attacker-controlled brands and fullVersionList arrays, and toDatabaseRows inserts every member into cu_useragent_clienthints without a bound. The route requires a valid revision context and low-privileged access; Wikimedia states that the affected code existed only on master and wmf branches, not in a released version.

The record

CVE
CVE-2023-45367
Published
Oct 9, 2023
Updated
Sep 19, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
T1499
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Oct 9, 2023CVE publishedPublication date reported by the CVE source.
  2. Sep 19, 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 vectornetwork
Required privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

6.5NIST NVDCVSS:3.1/AV:N/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)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

T1499Endpoint Denial of Service

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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