curl: FTP entrypath accepts 0xFF (Telnet IAC) through incomplete ISCNTRL filter, sent on wire via CWD on connection reuse

Summary A malicious FTP server can embed byte 0xFF Telnet IAC in the PWD response path. The ISCNTRL filter at lib/ftp.c:3095 expands to ISLOWCNTRLx || IS7Fx, which is unsigned charx entrypath line 3131 and sent verbatim via CWD %s on connection reuse line 849. I understand the KNOWNRISK.md and...