How Electronic Flight Bags Became a Target for Data Manipulation

TLDR: Researchers at DEF CON 2024 demonstrated how Electronic Flight Bag (EFB) applications, used by pilots for critical performance calculations, often lack integrity checks on their underlying data. By manipulating input parameters like aircraft weight and balance, an attacker can force the software to output incorrect performance data, potentially leading to dangerous takeoff or landing configurations. This research highlights a critical need for aviation software vendors to implement robust input validation and cryptographic signing for all performance-critical data files.

Aviation security has long been viewed through the lens of air-gapped systems and proprietary protocols, but the shift toward commercial off-the-shelf hardware in the cockpit has changed the threat model entirely. Pilots now rely on tablets running iOS or Android to perform weight and balance calculations, manage flight plans, and access performance data. When these applications lack basic integrity checks, they become prime targets for data manipulation. The research presented at DEF CON 2024 regarding Electronic Flight Bags (EFB) proves that we are no longer just looking at theoretical risks; we are looking at real-world operational hazards where a simple data injection can compromise flight safety.

The Mechanics of EFB Data Manipulation

At the core of the issue is the EFB’s reliance on external data sources to calculate performance metrics. Applications like the Airbus Onboard Performance Tool or similar third-party solutions ingest configuration files to determine how an aircraft will behave under specific conditions. The research identified that many of these applications fail to verify the integrity of these configuration files.

If an attacker gains access to the distribution channel or the local storage where these files reside, they can inject malicious parameters. Because the application assumes the data is trusted, it processes these inputs without question. For instance, by modifying the aircraft's empty weight or the center of gravity coordinates in a configuration file, the EFB will generate incorrect V-speeds (V1, VR, V2). If a pilot relies on these manipulated speeds for takeoff, the aircraft may not have sufficient lift or runway length, creating a high-risk scenario during a critical phase of flight.

Technical Vulnerabilities in Flight-Critical Software

The vulnerability here is a classic case of OWASP A03:2021-Injection, specifically targeting the data layer. The EFB applications act as a calculator, but they lack the necessary guardrails to ensure the input data hasn't been tampered with.

Consider a scenario where an EFB application parses a JSON or XML configuration file to load runway data. A payload designed to exploit this would look like this:

{
  "aircraft_type": "A320",
  "runway_data": {
    "length": 10000,
    "slope": 0.0,
    "surface_condition": "DRY"
  },
  "weight_parameters": {
    "empty_weight": 40000,
    "payload": 999999
  }
}

By injecting an unrealistic payload value, the application might crash or, worse, calculate performance data based on an impossible weight. The lack of cryptographic signing means the application cannot distinguish between a legitimate update from the airline's operations center and a malicious file placed by an attacker. This is compounded by the fact that many of these applications are updated via standard mobile device management (MDM) channels, which, if compromised, provide a direct path to the cockpit.

Real-World Applicability for Researchers

For a penetration tester or a security researcher, the EFB represents a fascinating target. These devices are often treated as "trusted" by the airline's IT infrastructure, meaning they might have access to internal networks for updates or data syncing. During an engagement, the focus should be on the update mechanism. How does the EFB receive its performance data? Is it over a secure, authenticated channel? Does the application perform a checksum or signature verification before loading the data?

If you are performing a bug bounty or a red team assessment, look for the following:

• Insecure File Storage: Can you access the application's data directory on the tablet?
• Lack of Signature Verification: Does the app load files that aren't signed by the vendor?
• Weak Input Validation: Can you feed the app extreme values that cause it to output nonsensical performance data?

The impact of a successful exploit is severe. Unlike a standard web application where the impact is data theft, here the impact is physical. You are influencing the decision-making process of the flight crew.

The Path to Better Defense

Defending these systems requires a shift in how aviation software is developed and certified. Vendors must move away from implicit trust in configuration files. Every data file ingested by an EFB must be cryptographically signed, and the application must verify this signature against a trusted root certificate before processing. Furthermore, developers should implement strict schema validation to ensure that input parameters remain within physically plausible bounds.

Patching these systems is notoriously difficult due to the stringent certification requirements in aviation. A change to a single line of code can trigger a lengthy recertification process with aviation authorities. However, the industry cannot use this as an excuse for leaving critical vulnerabilities unaddressed. If the software is safety-critical, it must be treated as such, with security baked into the design rather than bolted on as an afterthought.

Responsible disclosure is the only way forward. If you find a vulnerability in an EFB or any aviation-related system, work through the appropriate channels to ensure the vendor has time to fix it before going public. The goal is to make the skies safer, not to create panic. Keep digging into these systems, but keep your ethics as sharp as your technical skills.