Reusing Signatures

Submitted by (11) sseefried, also found by 0xA5DF, Bahurum, bin2chen, byndooa, cccz, GalloDaSballo, hyh, kankodu, Lambda, and minhquanym

Summary:

https://code4rena.com/reports/2022-08-rigor/#h-03-builder-can-call-communityescrow-again-to-reduce-debt-further-using-same-signatures https://code4rena.com/reports/2022-08-rigor/#h-04-project-funds-can-be-drained-by-reusing-signatures-in-some-cases https://code4rena.com/reports/2022-08-rigor/#m-13-in-projectsetcomplete-the-signature-can-be-reused-when-the-first-call-is-reverted-for-some-reason

Since there is no nonce in the data decoded at the beginning of function escrow, a builder can call the function multiple times reducing their debt as much as they wish.

Mitigation:

Modify function escrow to check this nonce and update it after the debt has been reduced.

TAGS: #sig

---