Greyhound Lines Inc. (owned by FirstGroup America Inc. – a subsidiary of FirstGroup Plc (UK))
Greyhound Lines Inc. (U.S.) provides intercity bus service across North America. It provides a personal ticketing kiosk services via its web and mobile applications for Greyhound customers. These applications help customers manage e-ticketing, mobile check-in, and the program.
Critical vulnerabilities were identified in the Greyhound APIs primarily due to insufficient authentication controls. Exploitation of these can result in the exposure of personally identifiable information (PII) for the customers who had joined the Road Rewards program. Additionally, an attacker can also remotely exploit an internet-exposed web service that hosts account information for Greyhound customers as well as other sensitive information. An attacker could use this vulnerability to gain access unrestricted access and completely take over user accounts belonging to affected members.
The impact of these discovered vulnerabilities is as follows. When exploited, attackers can perform the following:
- Hijack (take over the accounts) of more than a million people’s Greyhound Road Rewards accounts
- Use that information to access and update users’ personal information, such as personal addresses and contact information like email addresses and phone numbers
- View and update upcoming trips as well as users’ travel preferences (e.g., if a user frequently travels alone)
- 12/08/2018: Initial discovery
- Vendor contacted multiple times, no response
- 01/23/2019: Issue reported to US-CERT
- 02/19/2019: FirstGroup Plc made contact via Greyhound support
- 03/01/2019: Full vulnerability details disclosed to vendor
- No vendor follow-up and is no longer responsive (The vulnerabilities are still not fixed)
- 04/11/2019: Partial details for the vulnerabilities disclosed publicly
Priyank Nigam, Senior Security Analyst at Bishop Fox