PuTTY bug telnet-option-loop

This is a mirror. Follow this link to find the primary PuTTY web site.

summary: PuTTY violates RFC-854 option-loop prevention
class: bug: This is clearly an actual problem we want fixed.
difficulty: fun: Just needs tuits, and not many of them.
priority: medium: This should be fixed one day.
present-in: 0.57
fixed-in: 2005-03-17 780ca6231173169ac1f3d47c451565a4b50adad2 (0.58)

RFC 854 includes the following rule to prevent option-negotiation loops:

      b. If a party receives what appears to be a request to enter some
      mode it is already in, the request should not be acknowledged.
      This non-response is essential to prevent endless loops in the
      negotiation.  It is required that a response be sent to requests
      for a change of mode -- even if the mode is not changed.

PuTTY gets this wrong for options that it doesn't support.

Audit trail for this bug.

If you want to comment on this web site, see the Feedback page.

(last revision of this bug record was at 2016-12-27 11:40:22 +0000)