CVE-2021-21638Network attack vector

Credential capture via CSRF-triggered outbound connection

Published Mar 30, 2021 · Updated Aug 3, 2024

Cross-site request forgery in Jenkins Team Foundation Server Plugin 5.157.1 and earlier allows remote attackers to capture stored credentials. The affected HTTP endpoint accepts state-changing requests without requiring POST and connects to an attacker-specified URL with a supplied credential ID. Exploitation requires a victim's browser to issue the crafted request and a credential ID obtained through another method, exposing the selected Jenkins credential.

CVSS severity8.8
High
EPSS probability0.84%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Cross-site request forgery in Jenkins Team Foundation Server Plugin 5.157.1 and earlier allows remote attackers to capture stored credentials. The affected HTTP endpoint accepts state-changing requests without requiring POST and connects to an attacker-specified URL with a supplied credential ID. Exploitation requires a victim's browser to issue the crafted request and a credential ID obtained through another method, exposing the selected Jenkins credential.

The record

CVE
CVE-2021-21638
Published
Mar 30, 2021
Updated
Aug 3, 2024
Vendor
Jenkins Project
Product
Azure DevOps and Team Foundation Server Plugin
Classifications
CWE-352, CAPEC-62, T1190
Attack vector
network
Privileges
unauthenticated

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 privilegesunauthenticated

What is affected?

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

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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-352Cross-Site Request Forgery (CSRF)
CAPEC-62Cross Site Request Forgery
T1190Exploit Public-Facing Application

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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