In OpenZeppelin <=v4.4.0, 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, breaking the expectation that there is a single execution.
{
"severity": "HIGH",
"github_reviewed": true,
"cwe_ids": [
"CWE-665"
],
"nvd_published_at": "2022-02-04T12:15:00Z",
"github_reviewed_at": "2022-02-11T16:20:03Z"
}