A cross-site request forgery flaw was found in etcd 3.3.1 and earlier. An attacker can set up a website that tries to send a POST request to the etcd server and modify a key. Adding a key is done with PUT so it is theoretically safe (can't PUT from an HTML form or such) but POST allows creating in-order keys that an attacker can send.
{ "nvd_published_at": "2018-04-03T16:29:00Z", "cwe_ids": [ "CWE-352" ], "severity": "HIGH", "github_reviewed": true, "github_reviewed_at": "2021-05-12T18:17:42Z" }