FreeBSD-EN-20:02.nmount : nmount Invalid Pointer Dereference
Versions Affected : All verisons prior to FreeNAS 11.3-U1
Description
VFS option processing related to the nmount(2) system call was missing a length check.
This is generally only available to privileged users unless the vfs.usermount sysctl is changed from the default to allow non-privileged users the ability to mount file systems.
Workaround
No workaround is available. However, if the vfs.usermount sysctl has been changed to allow non-privileged users the ability to mount file systems, switching back to the default value of 0 will prevent non-privileged users from triggering the issue.
Mitigation
- Upgrade to FreeNAS 11.3-U1 or later