Magnetic locks are one of the most ubiquitous security
mechanisms in modern offices; however,
they are also the most misunderstood and therefore misinstalled.
Magnetic locks work by having a metal plate attached to either the door or the
frame and an electromagnet being installed on the other.
When a correct code or RFID badge is used against the door controller,
the current sent to the electromagnet is turned off
and the door can freely open.
Magnetic locks are vulnerable to several types of attack.
For example, if installed on the wrong side of the door,
which is very common, the wires could be cut,
rendering the device without power and the lock will unlock.
Another attack vector is that the bolts could be
removed and the door free to open.
Smaller locks can be forced open with air pump bags or just
barged open if opening away from you.
If you have the opportunity, placing a small bead of blue tack or chewing gum on
the magnet or the plate whilst the door is open will prevent the lock from
engaging again when the door tries to shut. Any distance between the plate and
the magnet will decrease the holding force.
This will allow you to access the door easier at a
later time in the engagement. Again,
remember to remove this before leaving the premises.