In jenkins before versions 2.44, 2.32.2 node monitor data could be viewed by low privilege users via the remote API. These included system configuration and runtime information of these nodes (SECURITY-343).
https://jenkins.io/security/advisory/2017-02-01/
https://github.com/jenkinsci/jenkins/commit/0f92cd08a19207de2cceb6a2f4e3e9f92fdc0899