CVE-2021-22231Public exploitNetwork attack vector

Profile-page denial via extension-stripping route collision

Published Jul 7, 2021 · Updated Aug 3, 2024

Denial of service in GitLab CE/EE 8.0 through 13.11.5, 13.12 through 13.12.5, and 14.0 through 14.0.1 lets remote authenticated users hide a profile. Rails routing treats a username suffix such as .html as a response-format extension and resolves the extensionless path instead of the intended user namespace. Exploitation requires an account with a specially suffixed username and another authenticated account able to create the matching extensionless group, causing requests for the victim's public profile URL to resolve to the group page.

CVSS severity3.5
Low
EPSS probability1.00%
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 GitLab CE/EE 8.0 through 13.11.5, 13.12 through 13.12.5, and 14.0 through 14.0.1 lets remote authenticated users hide a profile. Rails routing treats a username suffix such as .html as a response-format extension and resolves the extensionless path instead of the intended user namespace. Exploitation requires an account with a specially suffixed username and another authenticated account able to create the matching extensionless group, causing requests for the victim's public profile URL to resolve to the group page.

The record

CVE
CVE-2021-22231
Published
Jul 7, 2021
Updated
Aug 3, 2024
Vendor
GitLab
Product
GitLab
Classifications
Unavailable
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 7, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 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?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=>=13.12, <13.12.6
  2. Affected versionversion=>=14.0, <14.0.2
  3. Affected versionversion=>=8.0, <13.11.6

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

GitLab · GitLabversion=>=13.12, <13.12.6; version=>=14.0, <14.0.2; version=>=8.0, <13.11.6

Published CVSS scores

4.0NVDAV:N/AC:L/Au:S/C:N/I:N/A:P
4.3NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
3.5GitLab Inc.CVSS:3.1/AV:N/AC:L/PR:L/UI:R/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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

No sourced classifications are available.

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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