An issue was discovered in Mattermost Server before 5.2 and 5.1.1. Authorization could be bypassed if the channel name were not the same in the params and the body.
{
"versions": [
{
"introduced": "0"
},
{
"fixed": "5.1.1"
},
{
"introduced": "0"
},
{
"last_affected": "5.2.0-rc1"
},
{
"introduced": "0"
},
{
"last_affected": "5.2.0-rc2"
},
{
"introduced": "0"
},
{
"last_affected": "5.2.0-rc3"
},
{
"introduced": "0"
},
{
"last_affected": "5.2.0-rc4"
},
{
"introduced": "0"
},
{
"last_affected": "5.2.0-rc5"
},
{
"introduced": "0"
},
{
"last_affected": "5.2.0-rc6"
}
]
}