rotki before 1.44.2: unsalted SHA-256 premium sync key lets attackers brute-force encrypted cloud backups

Summary

rotki, an open-source crypto portfolio tracker, derived the encryption key for premium cloud-sync backups from a single unsalted SHA-256 hash of the user password. An attacker who obtains an uploaded backup blob can run GPU-parallel offline password guessing and decrypt the user database.

Affected

• rotki (rotkehlchen) versions before 1.44.2
• Fixed in 1.44.2 (per VulnCheck / NVD; see rotki PR #13401)

Impact

A decrypted backup exposes exchange API keys and secrets, tracked wallet addresses, and transaction history. The attacker must first obtain a backup blob; the weakness (CWE-916) then allows offline brute-forcing of the password. VulnCheck scores it CVSS 4.0 8.2 (High); the CVSS 3.1 score is 5.9 (Medium). Exploitation in the wild is not reported by the source.

Recommended actions

• Upgrade rotki to 1.44.2 or later
• Premium users with cloud sync enabled: rotate exchange API keys/secrets stored in rotki, and change the rotki password if it is weak or reused
• Prefer read-only, IP-restricted exchange API keys

Source & attribution

This 0xCERT advisory summarises a disclosure by VulnCheck (credit: George Chen): https://www.vulncheck.com/advisories/rotki-before-1.44.2-weak-key-derivation-for-premium-cloud-backup-encryption. Details may change; refer to the original source for the authoritative record.