CVE-2021-21695Network attack vector

Controller file listing via symlink traversal

Published Nov 4, 2021 · Updated Aug 3, 2024

Path traversal in FilePath#listFiles in Jenkins 2.318 and earlier allows remote authenticated users to list controller files via symlinks. The method follows symbolic links and returns entries outside directories granted to the agent because it omits stat permission checks on each result. Exploitation requires control of a connected agent; the exposed consequence is controller file-name and path disclosure, not file-content access by this operation alone.

CVSS severity8.8
High
EPSS probability2.15%
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 FilePath#listFiles in Jenkins 2.318 and earlier allows remote authenticated users to list controller files via symlinks. The method follows symbolic links and returns entries outside directories granted to the agent because it omits stat permission checks on each result. Exploitation requires control of a connected agent; the exposed consequence is controller file-name and path disclosure, not file-content access by this operation alone.

The record

CVE
CVE-2021-21695
Published
Nov 4, 2021
Updated
Aug 3, 2024
Vendor
Jenkins Project
Product
Jenkins
Classifications
CWE-59, T1083
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Nov 4, 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 <=2.318
  2. Affected versionversion=unspecified <=LTS 2.303.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Jenkins Project · Jenkinsversion=unspecified <=2.318; version=unspecified <=LTS 2.303.2

Published CVSS scores

6.8NIST NVDAV:N/AC:M/Au:N/C:P/I:P/A:P
8.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/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.

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 exploitUnconfirmed

Weakness, pattern, technique

CWE-59Improper Link Resolution Before File Access ('Link Following')
T1083File and Directory Discovery

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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