View at Official ubuntu advisory, NVD, CVE.org · CVE detail
Freshness: upstream tracker timestamp is available; use API updated time as primary recency signal.
CVE-2016-0762 low priority: Ubuntu including 3 source packages (tomcat6, tomcat7, tomcat8), 30 status rows across 10 suites (artful, bionic, cosmic, focal, precise, trusty, upstream, xenial, yakkety, zesty): DNE 10, not-affected 8, released 8, ignored 4.
The Realm implementations in Apache Tomcat versions 9.0.0.M1 to 9.0.0.M9, 8.5.0 to 8.5.4, 8.0.0.RC1 to 8.0.36, 7.0.0 to 7.0.70 and 6.0.0 to 6.0.45 did not process the supplied password if the supplied user name did not exist. This made a timing attack possible to determine valid user names. Note that the default configuration includes the LockOutRealm which makes exploitation of this vulnerability harder.