CVE-2020-2103
Jenkins Diagnostic page exposed session cookies
Description
Jenkins shows various technical details about the current user on the `/whoAmI` page. In [a previous fix](https://www.jenkins.io/security/advisory/2019-09-25/#SECURITY-1505), the `Cookie` header value containing the HTTP session ID was redacted. However, user metadata shown on this page could also include the HTTP session ID in Jenkins 2.218 and earlier, LTS 2.204.1 and earlier. This allows attackers able to exploit a cross-site scripting vulnerability to obtain the HTTP session ID value from this page. Jenkins 2.219, LTS 2.204.2 no longer prints out the affected user metadata that might contain the HTTP session ID. Additionally, we also redact values of further authentication-related HTTP headers in addition to `Cookie` on this page as a hardening.
How to fix CVE-2020-2103
To remediate CVE-2020-2103, upgrade the affected package to a fixed version below.
- —upgrade to 2.218.1 or later
- —upgrade to 2.219 or later
Is CVE-2020-2103 being exploited?
Moderate — EPSS is 45.2%. Track this CVE but it's not at the top of the prioritisation list.
Affected packages (2)
- from 0, < 2.218.1
- >= 2.205, < 2.219
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | MEDIUM5.4 | CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N |