The compilation daemon in Scala before 2.10.7, 2.11.x before 2.11.12, and 2.12.x before 2.12.4 uses weak permissions for private files in /tmp/scala-devel/${USER:shared}/scalac-compile-server-port, which allows local users to write to arbitrary class files and consequently gain privileges.
{
"versions": [
{
"introduced": "0"
},
{
"fixed": "2.10.7"
},
{
"introduced": "2.11.0"
},
{
"fixed": "2.11.12"
},
{
"introduced": "2.12.0"
},
{
"fixed": "2.12.4"
}
]
}