Insecure Use of HMAC-SHA1 For Session Signing in datahub

Summary

DataHub is an open-source metadata platform. The HMAC signature for DataHub Frontend sessions was being signed using a SHA-1 HMAC with the frontend secret key. SHA1 with a 10 byte key can be brute forced using sufficient resources (i.e. state level actors with large computational capabilities). DataHub Frontend was utilizing the Play LegacyCookiesModule with default settings which utilizes a SHA1 HMAC for signing. This is compounded by using a shorter key length than recommended by default for the signing key for the randomized secret value. An authenticated attacker (or attacker who has otherwise obtained a session token) could crack the signing key for DataHub and obtain escalated privileges by generating a privileged session cookie. Due to key length being a part of the risk, deployments should update to the latest helm chart and rotate their session signing secret. All deployments using the default helm chart configurations for generating the Play secret key used for signing are affected by this vulnerability. Version 0.11.1 resolves this vulnerability. All users are advised to upgrade. There are no known workarounds for this vulnerability.