CVE-2021-21669Network attack vector

Secret extraction and SSRF via external entities

Published Jun 18, 2021 · Updated Aug 3, 2024

XXE in Jenkins Generic Webhook Trigger Plugin 1.72 and earlier allows remote attackers to read controller secrets or cause SSRF. PostContentParameterResolver passes crafted XML webhook bodies to a DocumentBuilderFactory parser that permits DOCTYPE declarations and resolves attacker-supplied external entities. Exploitation requires a callable webhook configured to extract parameters with XPath; the parser can read controller files or make server-side requests.

CVSS severity9.8
Critical
EPSS probability25.75%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

XXE in Jenkins Generic Webhook Trigger Plugin 1.72 and earlier allows remote attackers to read controller secrets or cause SSRF. PostContentParameterResolver passes crafted XML webhook bodies to a DocumentBuilderFactory parser that permits DOCTYPE declarations and resolves attacker-supplied external entities. Exploitation requires a callable webhook configured to extract parameters with XPath; the parser can read controller files or make server-side requests.

The record

CVE
CVE-2021-21669
Published
Jun 18, 2021
Updated
Aug 3, 2024
Vendor
Jenkins Project
Product
Generic Webhook Trigger Plugin
Classifications
CWE-611, CAPEC-221, T1190
Attack vector
network
Privileges
Unavailable

Timeline

How it unfolded

  1. Jun 18, 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 <=1.72

What conditions does exploitation require?

Attack vectornetwork
Required privilegesUnavailable in this record.

What is affected?

Jenkins Project · Generic Webhook Trigger Pluginversion=unspecified <=1.72

Published CVSS scores

7.5NIST NVDAV:N/AC:L/Au:N/C:P/I:P/A:P
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.

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
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-611Improper Restriction of XML External Entity Reference
CAPEC-221Data Serialization External Entities Blowup
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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