Rejected reason: Neither filed by Chrome nor a valid security vulnerability.

A padding oracle vulnerability exists in Google Chrome’s AppBound cookie encryption mechanism due to observable decryption failure behavior in Windows Event Logs when handling malformed ciphertext in SYSTEM-DPAPI-encrypted blobs. A local attacker can repeatedly send malformed ciphertexts to the Chrome elevation service and distinguish between padding and MAC errors, enabling a padding oracle attack. This allows partial decryption of the SYSTEM-DPAPI layer and eventual recovery of the user-DPAPI encrypted cookie key, which is trivially decrypted by the attacker’s own context. This issue undermines the core purpose of AppBound Encryption by enabling low-privileged cookie theft through cryptographic misuse and verbose error feedback. Confirmed in Google Chrome with AppBound Encryption enabled. Other Chromium-based browsers may be affected if they implement similar COM-based encryption mechanisms. This behavior arises from a combination of Chrome’s AppBound implementation and th...

Уязвимость механизма обработки файлов cookie веб-браузера Google Chrome, связанная с недостатками механизма формирования отчетов об ошибках, позволяющая нарушителю похитить cookie-файлы