The privateaddresscheck ruby gem before 0.5.0 is vulnerable to a time-of-check time-of-use (TOCTOU) race condition due to the address the socket uses not being checked. DNS entries with a TTL of 0 can trigger this case where the initial resolution is a public address but the subsequent resolution is a private address.
{
"github_reviewed": true,
"github_reviewed_at": "2020-06-16T20:53:26Z",
"nvd_published_at": null,
"cwe_ids": [
"CWE-362"
],
"severity": "HIGH"
}