In Jenkins 2.355 and earlier, LTS 2.332.3 and earlier, an observable timing discrepancy on the login form allows distinguishing between login attempts with an invalid username, and login attempts with a valid username and wrong password, when using the Jenkins user database security realm.
[
{
"product": "Jenkins",
"vendor": "Jenkins project",
"versions": [
{
"lessThanOrEqual": "2.355",
"status": "affected",
"version": "unspecified",
"versionType": "custom"
},
{
"lessThanOrEqual": "LTS 2.332.3",
"status": "affected",
"version": "unspecified",
"versionType": "custom"
}
]
}
]