A technical analysis by ETH Zurich and Universit della Svizzera italiana found that cloud-based password managers Bitwarden, LastPass, and Dashlane are susceptible to password recovery attacks under a malicious-server threat model, identifying 12 attacks against Bitwarden, seven against LastPass, and six against Dashlane, and noting the three products together serve over 60 million users and nearly 125,000 businesses.
KEY FACTS
- Incident Multiple password recovery and integrity attacks against major cloud password managers
- Counts 12 attacks for Bitwarden, seven for LastPass, six for Dashlane
- Categories Key escrow failures, item-level encryption flaws, sharing feature abuse, legacy-code downgrade paths
- Scope Affects more than 60 million users and nearly 125,000 businesses
The analysis evaluates a malicious-server threat model that challenges zero-knowledge encryption guarantees, a different concern than end-to-end encryption for data in transit.
Attack techniques documented include exploitation of key escrow account recovery, flaws from encrypting items and settings separately coupled with unauthenticated metadata, misuse of sharing features, and downgrade attacks that rely on legacy compatibility.
Consequences described range from targeted integrity violations and metadata leakage to the recovery of passwords and the complete compromise of all vaults associated with an organization.
Vendors have applied countermeasures, including removal of legacy cryptography support, hardening of admin and sharing workflows, and active remediation of flagged issues. The analysis found no evidence that the vulnerabilities have been exploited in the wild.
WHY IT MATTERS
The findings show that server-side threat scenarios can undermine zero-knowledge guarantees and lead to password recovery or vault compromise. Organizations and users should follow vendor updates and apply mitigations to reduce exposure.