FTPServer.py in pyftpdlib before 0.2.0 allows remote attackers to cause a denial of service via a long command. References https://nvd.nist.gov/vuln/detail/CVE-2007-6739 https://github.com/giampaolo/pyftpdlib/issues/3 https://github.com/advisories/GHSA-5f3f-pg2c-cxcv
