CVE-2020-2253 Missing hostname validation in Email Extension Plugin

What is CVE-2020-2253?

CVE-2020-2253 is a medium-severity server-side request forgery vulnerability in Jenkins Email Extension Plugin, published on 16 Sep 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

Jenkins Email Extension Plugin 2.75 and earlier does not perform hostname validation when connecting to the configured SMTP server.

Weakness: CWE-295

Which versions are affected by CVE-2020-2253?

2 open source packages ship an affected version, including org.jenkins-ci.plugins:email-ext. It affects 1 product.

Products include Jenkins Email Extension.

How do I fix CVE-2020-2253?

Upgrade org.jenkins-ci.plugins:email-ext to 2.76 or later.

Upgrade, and send outbound requests through an allow-list that blocks internal addresses. More about Server-side request forgery.

Is CVE-2020-2253 being exploited?

There is no known exploitation of CVE-2020-2253 in the wild and no public exploit code.

Other vulnerabilities in Jenkins Email Extension Plugin

• CVE-2023-25765 Sandbox escape in Jenkins Email Extension Plugin Critical 9.9
• CVE-2019-1003032 Script security sandbox bypass in Jenkins Email Extension Plugin Critical 9.9
• CVE-2026-48920 Jenkins Email Extension Plugin: Attackers able to control email content may specify `file:` URLs for images to read arbitrary files from Jenkins controller filesystem High 8.8
• CVE-2020-2232 Jenkins Email Extension Plugin SMTP password transmitted and displayed in plain text High 7.5
• CVE-2018-1000176 Jenkins Email Extension Plugin showed plain text SMTP password in configuration form field Medium 6.5

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-4qrj-99r6-jfrh.