CVE-2020-2253: Medium severity jenkins email extension template vulnerability
Email Extension Plugin 2.75 and earlier does not perform hostname validation when connecting to the configured SMTP server. This lack of validation could be abused using a man-in-the-middle attack to intercept these connections.
Email Extension Plugin 2.76 validates the SMTP hostname when connecting via TLS by default. In Email Extension Plugin 2.75 and earlier, administrators can set the Java system property mail.smtp.ssl.checkserveridentity to true on startup to enable this protection. Alternatively, this protection can be enabled (or disabled in the new version) via the 'Advanced Email Properties' field in the plugin’s configuration in Configure System.
In case of problems, this protection can be disabled again by setting mail.smtp.ssl.checkserveridentity to false using either method.
Other sources
Jenkins Email Extension Plugin 2.75 and earlier does not perform hostname validation when connecting to the configured SMTP server.
Affected Software
Event History
Frequently Asked Questions
What is CVE-2020-2253?
CVE-2020-2253 is a vulnerability in Jenkins Email Extension Plugin 2.75 and earlier versions that allows man-in-the-middle attacks.
What is the severity of CVE-2020-2253?
CVE-2020-2253 has a severity rating of medium.
Which software versions are affected by CVE-2020-2253?
Jenkins Email Extension Plugin versions 2.75 and earlier versions are affected by CVE-2020-2253.
How can CVE-2020-2253 be exploited?
CVE-2020-2253 can be exploited by performing a man-in-the-middle attack to intercept the connections.
Is there a fix for CVE-2020-2253?
Yes, the fix for CVE-2020-2253 is available in Email Extension Plugin version 2.76.