CVE-2020-2099Network attack vector

Agent impersonation via reused encryption parameters

Published Jan 29, 2020 · Updated Aug 4, 2024

Authentication bypass in Jenkins weekly 2.218 and earlier and LTS 2.204.1 and earlier allows remote attackers to impersonate inbound agents. Inbound TCP Agent Protocol/3 reuses encryption parameters, letting an attacker who knows an agent name derive its connection secret. The exposed protocol and an existing agent name are required; the recovered secret authenticates an attacker-controlled agent to the controller.

CVSS severity8.6
High
EPSS probability1.01%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authentication bypass in Jenkins weekly 2.218 and earlier and LTS 2.204.1 and earlier allows remote attackers to impersonate inbound agents. Inbound TCP Agent Protocol/3 reuses encryption parameters, letting an attacker who knows an agent name derive its connection secret. The exposed protocol and an existing agent name are required; the recovered secret authenticates an attacker-controlled agent to the controller.

The record

CVE
CVE-2020-2099
Published
Jan 29, 2020
Updated
Aug 4, 2024
Vendor
Jenkins Project
Product
Jenkins
Classifications
CWE-330, T1078
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 29, 2020CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 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 <=2.213
  2. Affected versionversion=unspecified <=LTS 2.204.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Jenkins Project · Jenkinsversion=unspecified <=2.213; version=unspecified <=LTS 2.204.1

Published CVSS scores

7.5NIST National Vulnerability DatabaseAV:N/AC:L/Au:N/C:P/I:P/A:P
8.6NIST National Vulnerability DatabaseCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:L

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-330Use of Insufficiently Random Values
T1078Valid Accounts

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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