GHSA-chh6-ppwq-jh92: Improper Preservation of Permissions in etcd

Ubuntu Security Notice 5628-1 - It was discovered that etcd incorrectly handled certain specially crafted WAL files. An attacker could possibly use this issue to cause a denial of service. It was discovered that etcd incorrectly handled directory permissions when trying to create a directory that exists already. An attacker could possibly use this issue to obtain sensitive information. It was discovered that etcd incorrectly handled endpoint setup. An attacker could possibly use this issue to cause a denial of service.

In etcd before versions 3.3.23 and 3.4.10, certain directory paths are created (etcd data directory and the directory path when provided to automatically generate self-signed certificates for TLS connections with clients) with restricted access permissions (700) by using the os.MkdirAll. This function does not perform any permission checks when a given directory path exists already. A possible workaround is to ensure the directories have the desired permission (700).