The U.S. aircraft register, updated daily
Special conditions · aircraft

Special Conditions: Airbus Model A318, A319, A320 and A321 Series Airplanes; Electronic System Security Protection From Unauthorized External Access

Special conditions are rules the FAA writes for one design when the standard certification rules do not cover something new about it. These were published June 27, 2018 for Airbus, covering the A321, A320, A319, A318. System: other and general.

What it applies to

Applicant
Airbus
Makes
Airbus
Models
A321, A320, A319, A318
On this site
Airbus A319 329 registered
Airbus A320 797 registered
Airbus A321 931 registered
Published
June 27, 2018
Effective
June 27, 2018
The FAA's document
On the FAA's site

The FAA's summary their words, unchanged

These special conditions are issued for the Airbus Model A318, A319, A320 and A321 series airplanes. These airplanes will have a novel or unusual design feature when compared to the state of technology envisioned in the airworthiness standards for transport category airplanes. This design feature is airplane electronic systems and networks that allow access from external sources (e.g., wireless devices, internet connectivity) to the airplane's internal electronic components. The applicable airworthiness regulations do not contain adequate or appropriate safety standards for this design feature. These special conditions contain the additional safety standards that the Administrator considers necessary to establish a level of safety equivalent to that established by the existing airworthiness standards.

Source: FAA special conditions (final) from the Dynamic Regulatory System; the Federal Register carries the same notices.