Root shell on a credit card terminal (stefan-gloor.ch)

Article summary

A security researcher reverse-engineered a credit card terminal, the Worldline Yomani XR, and found a root shell, but determined it was not as significant a risk as initially thought due to the terminal's architecture, which separates secure and insecure components. The secure component handles sensitive data, such as card information, and is not accessible from the Linux system. The researcher found that the Linux system, which handles networking and updates, can be compromised, but this does not necessarily allow access to sensitive data. The terminal's tamper protection mechanism is triggered when the device is opened, but the researcher found that the serial port can still be accessed from the outside.

Main themes

• payment terminal security
• tamper protection
• secure and insecure components
• payment network security
• cryptography
• physical access and security
• denial of service attacks
• firmware updates and security

What commenters say

• Having physical access to a payment terminal does not necessarily allow for the theft of sensitive data, such as credit card numbers.
• The use of separate processors for secure and insecure components in payment terminals is an effective security measure.
• The security of payment terminals relies not only on the terminal itself, but also on the security of the payment network and the cryptography used.
• Compromising a payment terminal's Linux system may not allow for the theft of sensitive data, but could still be used for denial of service attacks or other malicious purposes.
• The security of modern payment cards, such as chip cards, relies on the card itself, rather than the terminal, to protect sensitive data.
• Payment terminals with magnetic stripe readers are more vulnerable to exploitation than those without.
• The update mechanism for the secure firmware of payment terminals may be vulnerable to exploitation if not properly secured.