CVE-2021-21637Network attack vector

Credential theft via unchecked outbound connection

Published Mar 30, 2021 · Updated Aug 3, 2024

Missing authorization in Jenkins Team Foundation Server Plugin 5.157.1 and earlier lets remote authenticated users capture stored credentials. An HTTP endpoint accepts a caller-supplied URL and credential ID, then initiates a connection without checking the caller's permission. Overall/Read access and a credential ID obtained separately are required; the resulting outbound request discloses the selected Jenkins credential.

CVSS severity6.5
Medium
EPSS probability0.97%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Missing authorization in Jenkins Team Foundation Server Plugin 5.157.1 and earlier lets remote authenticated users capture stored credentials. An HTTP endpoint accepts a caller-supplied URL and credential ID, then initiates a connection without checking the caller's permission. Overall/Read access and a credential ID obtained separately are required; the resulting outbound request discloses the selected Jenkins credential.

The record

CVE
CVE-2021-21637
Published
Mar 30, 2021
Updated
Aug 3, 2024
Vendor
Jenkins Project
Product
Azure DevOps and Team Foundation Server Plugin
Classifications
CWE-862, T1187
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 30, 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 <=5.157.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Jenkins Project · Azure DevOps and Team Foundation Server Pluginversion=unspecified <=5.157.1

Published CVSS scores

6.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
4.0NIST NVDAV:N/AC:L/Au:S/C:P/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 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-862Missing Authorization
T1187Forced Authentication

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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