CVE-2021-21683Network attack vector

Arbitrary file read via absolute Windows paths

Published Oct 6, 2021 · Updated Aug 3, 2024

Path traversal in Jenkins 2.314 and earlier and LTS 2.303.1 and earlier allows remote authenticated users to read arbitrary files via the Windows file browser. DirectoryBrowserSupport accepts an absolute path fragment and joins it to the browsing root, allowing workspace, artifact, or userContent requests to escape their intended directory. Overall/Read permission on a Windows controller or Job/Workspace permission on a Windows agent is required, and the consequence is unauthorized confidentiality loss without documented write or service-interruption impact.

CVSS severity6.5
Medium
EPSS probability2.17%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Path traversal in Jenkins 2.314 and earlier and LTS 2.303.1 and earlier allows remote authenticated users to read arbitrary files via the Windows file browser. DirectoryBrowserSupport accepts an absolute path fragment and joins it to the browsing root, allowing workspace, artifact, or userContent requests to escape their intended directory. Overall/Read permission on a Windows controller or Job/Workspace permission on a Windows agent is required, and the consequence is unauthorized confidentiality loss without documented write or service-interruption impact.

The record

CVE
CVE-2021-21683
Published
Oct 6, 2021
Updated
Aug 3, 2024
Vendor
Jenkins Project
Product
Jenkins
Classifications
CWE-22, T1083
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Oct 6, 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=unspecified <=2.314
  2. Affected versionversion=unspecified <=LTS 2.303.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Jenkins Project · Jenkinsversion=unspecified <=2.314; version=unspecified <=LTS 2.303.1

Published CVSS scores

4.0NVDAV:N/AC:L/Au:S/C:P/I:N/A:N
6.5NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-22Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
T1083Path and Directory Discovery

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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