Jenkins Team Foundation Server Plugin 5.157.1 and earlier stores a webhook secret unencrypted in its global configuration file on the Jenkins controller where it can be viewed by attackers with access to the Jenkins controller file system.
https://jenkins.io/security/advisory/2020-09-01/#SECURITY-1506
https://jenkins.io/security/advisory/2020-09-01/#SECURITY-1506
http://www.openwall.com/lists/oss-security/2020/09/01/3
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-2249