"In the interim this protocol ensures our cockpits remain secure", King said in a statement.
The spokeswoman said the breach in security measures was not the result of hacking and did not cause any flights to be delayed or canceled.
In messages obtained by CNN, the airline's pilots were told "flight deck access procedures may have been compromised and a corrective plan was being established". The Air Line Pilots Association, which represents United pilots, said this weekend's incident showed the need for secondary barriers on all US airliners. Instead, an airline attendant mistakenly posted them online without realizing what they contained.
A pilot who spoke with CBS News also believes that cockpit doors on each United plane will need to be manually reprogrammed with different access codes.
Rusty Aimer, a retired United pilot who is now an aviation consultant, said changing the codes "should not create a big security concern".
However, the company was quick to clarify that this particular incident was an accident, rather than an intentional data security breach.
The Air Line Pilots Association, the largest pilot union in the world, has since said that the problem has been fixed.
Still in recovery mode from a string of public relations disasters that included a dead rabbit, two live scorpions, and the infamous "reaccommodation" of a passenger on an overbooked flight, United Airlines faced yet another crisis over the weekend.
According to FAA regulations, the cockpit door should be able to "resist penetration by small arms fire and grenade shrapnel". Authorities said at the time the suicidal co-pilot locked out the captain when he left the cockpit momentarily.