Openzeppelin Contract Vulnerability

[code423n4]

Handle

defsec

Vulnerability details

Impact

Initializer functions that are invoked separate from contract creation (the most prominent example being minimal proxies) may be reentered if they make an untrusted non-view external call.

Once an initializer has finished running it can never be re-executed. However, an exception put in place to support multiple inheritance made reentrancy possible in the scenario described above, breaking the expectation that there is a single execution.

Note that upgradeable proxies are commonly initialized together with contract creation, where reentrancy is not feasible, so the impact of this issue is believed to be minor.

Proof of Concept

1. Go to contracts directory.

2. On the package.json, openzeppelin 4.1.0 is defined.

https://github.com/code-423n4/2022-01-timeswap/blob/main/Timeswap/Timeswap-V1-Convenience/package.json

Tools Used

None

Recommended Mitigation Steps

Avoid untrusted external calls during initialization.

A fix is included in the version v4.4.1 of @openzeppelin/contracts and @openzeppelin/contracts-upgradeable.

Reference

GHSA-9c22-pwxw-p6hx

[Mathepreneur]

We are not using initializer.

[0xean]

closing as invalid.