Vault Vulnerable to Cache-Timing Attacks During Seal and Unseal Operations

Summary

HashiCorp Vault's implementation of Shamir's secret sharing used precomputed table lookups, and was vulnerable to cache-timing attacks. An attacker with access to, and the ability to observe a large number of unseal operations on the host through a side channel may reduce the search space of a brute force effort to recover the Shamir shares. Fixed in Vault 1.13.1, 1.12.5, and 1.11.9.