CVE-2021-22203Public exploitNetwork attack vector

Arbitrary file read via AsciiDoc counter substitution

Published Apr 2, 2021 · Updated Aug 3, 2024

Arbitrary file read in GitLab CE/EE 13.7.9 through 13.8.6, 13.9 through 13.9.4, and 13.10.0 allows remote attackers to read server files. When Kroki is enabled, AsciiDoc counter substitution restores the disabled kroki-plantuml-include attribute, causing diagram rendering to read attacker-selected local paths and encode their contents in the image URL. Kroki must be enabled; GitLab assesses the network path as requiring neither authentication nor user interaction.

CVSS severity9.8
Critical
EPSS probability1.39%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Arbitrary file read in GitLab CE/EE 13.7.9 through 13.8.6, 13.9 through 13.9.4, and 13.10.0 allows remote attackers to read server files. When Kroki is enabled, AsciiDoc counter substitution restores the disabled kroki-plantuml-include attribute, causing diagram rendering to read attacker-selected local paths and encode their contents in the image URL. Kroki must be enabled; GitLab assesses the network path as requiring neither authentication nor user interaction.

The record

CVE
CVE-2021-22203
Published
Apr 2, 2021
Updated
Aug 3, 2024
Vendor
GitLab
Product
GitLab
Classifications
T1005
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 2, 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=>=13.10, <13.10.1
  2. Affected versionversion=>=13.7.9, <13.8.7
  3. Affected versionversion=>=13.9, <13.9.5

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

GitLab · GitLabversion=>=13.10, <13.10.1; version=>=13.7.9, <13.8.7; version=>=13.9, <13.9.5

Published CVSS scores

9.8NIST NVDCVSS:3.1/AV:N/AC:L/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.

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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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

T1005Data from Local System

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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