[JENKINS:SECURITY-1656] Passwords transmitted in plain text by `StashBranchParameter`

StashBranchParameter stores Stash API passwords in its global configuration file org.jenkinsci.plugins.StashBranchParameter.StashBranchParameterDefinition.xml on the Jenkins controller as part of its configuration.

While the password is stored encrypted on disk, it is transmitted in plain text as part of the configuration form by StashBranchParameter 0.3.0 and earlier.
This can result in exposure of the password through browser extensions, cross-site scripting vulnerabilities, and similar situations.

This only affects Jenkins before 2.236, including 2.235.x LTS, as Jenkins 2.236 introduces a security hardening that transparently encrypts and decrypts data used for a Jenkins password form field.

As of publication of this advisory, there is no fix.