A vulnerability was found in nse_libssh2.cc in Nmap 7.70 is subject to a denial of service condition due to a double free when an SSH connection fails, as demonstrated by a leading \n character to ssh-brute.nse or ssh-auth-methods.nse.Nmap through 7.70, when the -sV option is used, allows remote attackers to cause a denial of service via a crafted TCP-based service.