22 Dec 2021 [security] [services]

Cake Wallet publishes Inference's audit of Thorchain's Monero multisig implementation

Cake Wallet1 has published Inference2’s audit3 of Thorchain4’s Monero multisig implementation5:

A few weeks ago, Cake Wallet reached out to auditors to review Thorchain’s Monero multisig implementation. This is a critical part of Thorchain’s code, since it is expected to be used to store native XMR used for liquidity providing and other functions of the Thorchain network.

The audit uncovered 2 potential security issues with low impact:

- S-CKW-001: [sign_multisig_parallel()] Unchecked parsing result (Exploitability: medium / Impact: low)
- S-CKW-002: [accu_multisig()] Undefined Behavior with Empty Signatures (Exploitability: low / Impact: low)

The report also produced 5 observations related to defense-in-depth, reliability, and performance:

- O-CKW-01: [Dockerfile] Leaked IP address
- O-CKW-02: [Dockerfile] unused ports
- O-CKW-03: Unused variables
- O-CKW-04: [RPC] on_check_transaction() can fail if two destinations have
the same amount
- O-CKW-05: [RPC] on_check_transaction() inconsistent failure handling

Before Thorchain can use Monero multisig, some PRs6 still have to be reviewed and merged. That would fix the recently disclosed vulnerabilities in the implementation of Monero multisignature wallets code, as previously reported7.

More details about this development can be found in Cake’s announcement thread8.

  1. https://cakewallet.com 

  2. https://inference.ag/ 

  3. https://cakewallet.com/assets/docs/2021-12-20-cakewallet-thorchain-audit.pdf (PDF) 

  4. https://thorchain.org/ 

  5. https://gitlab.com/thorchain/tss/monero-sign/ 

  6. https://github.com/monero-project/monero/pull/8113, https://github.com/monero-project/monero/pull/8114 

  7. /vulnerabilities-identified-monero-multisignature-wallet-code/ 

  8. https://libredd.it/r/Monero/comments/rlo8cz