Mattermost versions 11.0.x <= 11.0.2, 10.12.x <= 10.12.1, 10.11.x <= 10.11.4, 10.5.x <= 10.5.12 fail to to verify that the token used during the code exchange originates from the same authentication flow, which allows an authenticated user to perform account takeover via a specially crafted email address used when switching authentication methods and sending a request to the /users/login/sso/code-exchange endpoint. The vulnerability requires ExperimentalEnableAuthenticationTransfer to be enabled (default: enabled) and RequireEmailVerification to be disabled (default: disabled).
{
"versions": [
{
"introduced": "10.5.0"
},
{
"fixed": "10.5.13"
},
{
"introduced": "10.11.0"
},
{
"fixed": "10.11.5"
},
{
"introduced": "10.12.0"
},
{
"fixed": "10.12.2"
},
{
"introduced": "11.0.0"
},
{
"fixed": "11.0.3"
}
]
}