Nextcloud Server before 9.0.52 & ownCloud Server before 9.0.4 are not properly verifying restore privileges when restoring a file. The restore capability of Nextcloud/ownCloud was not verifying whether a user has only read-only access to a share. Thus a user with read-only access was able to restore old versions.
{
"versions": [
{
"introduced": "0"
},
{
"fixed": "9.0.52"
},
{
"introduced": "0"
},
{
"fixed": "9.0.4"
}
]
}