Nextcloud Server before 9.0.54 and 10.0.1 & ownCloud Server before 9.1.2, 9.0.6, and 8.2.9 suffer from SMB User Authentication Bypass. Nextcloud/ownCloud include an optional and not by default enabled SMB authentication component that allows authenticating users against an SMB server. This backend is implemented in a way that tries to connect to a SMB server and if that succeeded consider the user logged-in. The backend did not properly take into account SMB servers that have any kind of anonymous auth configured. This is the default on SMB servers nowadays and allows an unauthenticated attacker to gain access to an account without valid credentials. Note: The SMB backend is disabled by default and requires manual configuration in the Nextcloud/ownCloud config file. If you have not configured the SMB backend then you’re not affected by this vulnerability.
[
{
"product": "Nextcloud Server & ownCloud Server Nextcloud Server before 9.0.54 and 10.0.1 & ownCloud Server before 9.1.2, 9.0.6, and 8.2.9",
"vendor": "n/a",
"versions": [
{
"status": "affected",
"version": "Nextcloud Server & ownCloud Server Nextcloud Server before 9.0.54 and 10.0.1 & ownCloud Server before 9.1.2, 9.0.6, and 8.2.9"
}
]
}
]
github.com/nextcloud/apps/commit/b85ace6840b8a6704641086bc3b8eb8e81cb2274
github.com/nextcloud/apps/commit/decb91fd31f4ffab191cbf09ce4e5c55c67a4087
github.com/owncloud/apps/commit/16cbccfc946c8711721fa684d78135ca1fb64791
github.com/owncloud/apps/commit/5d47e7b52646cf79edadd78ce10c754290cbb732
github.com/owncloud/apps/commit/a0e07b7ddd5a5fd850a6e07f8457d05b76a300b3
hackerone.com/reports/148151
nextcloud.com/security/advisory/?id=nc-sa-2016-006
owncloud.org/security/advisory/?id=oc-sa-2016-017
rhinosecuritylabs.com/2016/10/operation-ownedcloud-exploitation-post-exploitation-persistence/