GNU bug report logs - #37344
rcirc: nil gets interpreted as a nickname

Previous Next

Full log

Message #5 received at submit <at> debbugs.gnu.org (full text, mbox):

From: Naïm Favier <n.emacs <at> monade.li>
To: bug-gnu-emacs <at> gnu.org
Subject: rcirc: nil gets interpreted as a nickname
Date: Sun, 8 Sep 2019 20:58:59 +0200

Severity: normal

Ever since I changed my nickname to "nil" on Freenode, I've been
getting occasional private messages from unknown users consisting of a
single empty CTCP ACTION. After a bit of investigating, it turned out
they all used rcirc. The situation was clear at that point: somewhere
in rcirc's source code, a nil value is being implicitly converted to a
string and used as the target of a PRIVMSG command.

The bug seems to be reproducible by issuing "/me" (without arguments)
inside a server buffer: the "nil" user on that server gets sent an
empty ACTION.

Suggested fix: in rcirc-send-privmsg, fail if target is nil. It might
be useful to check other places where the "%s" format is used, to
discover similar bugs.

Previous Next

GNU bug tracking system
Copyright (C) 1999 Darren O. Benham, 1997,2003 nCipher Corporation Ltd, 1994-97 Ian Jackson.