OwnableTwoStep allows a pending owner to accept ownership after the original owner has renounced ownership in cairo-contracts

Vulnerability Description

Cairo-Contracts are OpenZeppelin Contracts written in Cairo for Starknet, a decentralized ZK Rollup. This vulnerability can lead to unauthorized ownership transfer, contrary to the original owner's intention of leaving the contract without an owner. It introduces a security risk where an unintended party (pending owner) can gain control of the contract after the original owner has renounced ownership. This could also be used by a malicious owner to simulate leaving a contract without an owner, to later regain ownership by previously having proposed himself as a pending owner. This issue has been addressed in release version 0.16.0. All users are advised to upgrade. There are no known workarounds for this vulnerability.

References

• https://github.com/OpenZeppelin/cairo-contracts/security/advisories/GHSA-w2px-25pm-2cf9
• https://github.com/OpenZeppelin/cairo-contracts/commit/ef87d7847980e0cf83f4b7f3ff23e6590fb643ec
• https://github.com/OpenZeppelin/cairo-contracts/releases/tag/v0.16.0