Description
ZF FROST is a Rust implementation of FROST (Flexible Round-Optimised Schnorr Threshold signatures). In versions 2.0.0 through 2.1.0, refresh shares with smaller min_signers will reduce security of group. The inability to change min_signers (i.e. the threshold) with the refresh share functionality (frost_core::keys::refresh module) was not made clear to users. Using a smaller value would not decrease the threshold, and attempts to sign using a smaller threshold would fail. Additionally, after refreshing the shares with a smaller threshold, it would still be possible to sign with the original threshold, potentially causing a security loss to the participant's shares. This issue is fixed in version 2.2.0.
Problem types
CWE-325: Missing Cryptographic Step
Product status
References
github.com/.../frost/security/advisories/GHSA-wgq8-vr6r-mqxm
github.com/...ommit/379ef689c733b3d9c80fd409071d4f3af4dafed2
github.com/...oundation/frost/releases/tag/frost-core/v2.2.0
