Exploiting Leakage in Password Managers via Injection Attacks

Abstract: This work explores injection attacks against password managers. In this setting, the adversary (only) controls their own application client, which they use to "inject" chosen payloads to a victim's client via, for example, sharing credentials with them. The injections are interleaved with adversarial observations of some form of protected state (such as encrypted vault exports or the network traffic received by the application servers), from which the adversary backs out confidential information. We uncover a series of general design patterns in popular password managers that lead to vulnerabilities allowing an adversary to efficiently recover passwords, URLs, usernames, and attachments. We develop general attack templates to exploit these design patterns and experimentally showcase their practical efficacy via analysis of ten distinct password manager applications. We disclosed our findings to these vendors, many of which deployed mitigations.