ProFTPD before 1.3.6b and 1.3.7rc before 1.3.7rc2 allows remote unauthenticated denial-of-service due to incorrect handling of overly long commands because main.c in a child process enters an infinite loop.

References

• https://nvd.nist.gov/vuln/detail/CVE-2019-18217
• proftpd/proftpd#846
• https://github.com/proftpd/proftpd/blob/1.3.6/NEWS
• https://github.com/proftpd/proftpd/blob/1.3.6/RELEASE_NOTES
• https://github.com/proftpd/proftpd/blob/master/NEWS
• https://github.com/proftpd/proftpd/blob/master/RELEASE_NOTES
• https://cert-portal.siemens.com/productcert/pdf/ssa-940889.pdf
• https://lists.debian.org/debian-lts-announce/2019/10/msg00036.html
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/NJDQRVZTILBX4BUCTIRKP2WBHDHDCJR5
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RB2FPAWDWXT5ALAFIC5Y3RSEMXSFL6H2
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/YLRPYEEMQJVAXO2SXRGOQ4HBFEEPCNXG
• https://seclists.org/bugtraq/2019/Nov/7
• https://security.gentoo.org/glsa/202003-35
• https://www.debian.org/security/2019/dsa-4559
• http://lists.opensuse.org/opensuse-security-announce/2020-01/msg00009.html