CVE-2020-2103Network attack vector

Session ID disclosure via exposed user metadata

Published Jan 29, 2020 · Updated Aug 4, 2024

Information disclosure in Jenkins 2.218 and earlier and LTS 2.204.1 and earlier allows attackers to obtain HTTP session IDs via /whoAmI. The diagnostic page redacts the Cookie header but prints user metadata that can contain the same HTTP session identifier. Exploitation requires a separate cross-site scripting flaw and victim interaction; the exposed identifier enables takeover of the affected Jenkins session.

CVSS severity5.4
Medium
EPSS probability7.04%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Information disclosure in Jenkins 2.218 and earlier and LTS 2.204.1 and earlier allows attackers to obtain HTTP session IDs via /whoAmI. The diagnostic page redacts the Cookie header but prints user metadata that can contain the same HTTP session identifier. Exploitation requires a separate cross-site scripting flaw and victim interaction; the exposed identifier enables takeover of the affected Jenkins session.

The record

CVE
CVE-2020-2103
Published
Jan 29, 2020
Updated
Aug 4, 2024
Vendor
Jenkins Project
Product
Jenkins
Classifications
CWE-200, T1539
Attack vector
network
Privileges
authenticated

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

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=unspecified <=2.218
  2. Affected versionversion=unspecified <=LTS 2.204.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Jenkins Project · Jenkinsversion=unspecified <=2.218; version=unspecified <=LTS 2.204.1

Published CVSS scores

5.4NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
4.0NIST NVDAV:N/AC:L/Au:S/C:N/I:P/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-200Exposure of Sensitive Information to an Unauthorized Actor
T1539Steal Web Session Cookie

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

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo