Amazon Kindle: a Thales engineer uncovered a critical vulnerability

At the latest Black Hat Europe conference, which brought together cybersecurity experts and researchers in London, Valentino Ricotta, an analyst with Thales’ cyber teams, outlined a chain of vulnerabilities that could be used to compromise a device from a malicious file. His aim was to show how a common practice, sideloading (that is, manually transferring books from third-party sites), can turn a Kindle into a gateway to a user’s digital ecosystem.

The key role played by “parsing”

Central to the demonstration is a mechanism little known to the general public: parsing. When a file is added to the e-reader, the system analyses it to extract metadata (such as the title, author, and cover) and to prepare it for display. This automated background processing is a classic point of vulnerability: it has to handle a multitude of formats, special cases, and sometimes deliberately corrupted data.

By targeting the way certain files are processed, Valentino Ricotta showed that, during this analysis phase, it was possible to trigger the execution of unintended instructions. Combined with a second flaw in the virtual keyboard, the vulnerability enabled remote code execution with elevated privileges. By extracting the session cookies stored on the device — the tokens that keep a user signed in — an attacker could access the associated account, view personal data and exploit saved payment methods, without ever having to enter a password.

In keeping with Thales’ commitment to ethical hacking, the vulnerabilities were reported to Amazon and subsequently patched.

Beyond the Kindle: keeping connected ecosystems secure

This episode is a reminder of an often underestimated reality: cybersecurity is not confined to critical infrastructure, but extends to everyday devices as well. Once a technology is connected, it can become an entry point that malicious actors may exploit.

It also highlights the sharpness of cyber teams, able to anticipate threats by thinking like an attacker, analyse complex systems that combine software and hardware components, and uncover vulnerabilities where few would think to look. The value is also measured in the outcome: assessing the risk, producing robust evidence, and supporting remediation through responsible disclosure.

At Thales, this expertise rests on complementary capabilities (reverse engineering, analysis of physical and software architectures, and a deep understanding of information processing chains) as well as the ability to translate a technical weakness into a tangible impact for the user, the organisation and, more broadly, the digital ecosystem.