Don't allow stray \r or \n in command parameters

If ngircd receives an input line like "COMMAND arg\nIRRELEVANT\r\n",
"arg\nIRRELEVANT" is passed as an argument to COMMAND. This can lead
to output like:

:ngircd.test.server 322 nick #chan 1 :
topicwithprecedingnewline
:ngircd.test.server 322 nick #nxtchan 1 :
[..]

Worse, this allows clients to piggyback irc commands, e.g.
"TOPIC #a :test\n:fake!~a@nonexistant JOIN :#a\r\n", which
causes the client to receive a JOIN command during /LIST output.

Bug reported by Scott Perry, first patch by Florian Westphal.

diff --git a/src/ngircd/parse.c b/src/ngircd/parse.c
index ef2dbbba0bc6d874f886e6a311bef9a233887d6d..00ae3cd7e93d5f415a596d3d4c6b50ffb27c7817 100644 (file)
--- a/src/ngircd/parse.c
+++ b/src/ngircd/parse.c
@@ -1,6 +1,6 @@
 /*
  * ngIRCd -- The Next Generation IRC Daemon
- * Copyright (c)2001,2002 by Alexander Barton (alex@barton.de)
+ * Copyright (c)2001-2008 Alexander Barton (alex@barton.de)
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -9,11 +9,8 @@
  * Please read the file COPYING, README and AUTHORS for more information.
  */
 
-
 #include "portab.h"
 
-static char UNUSED id[] = "$Id: parse.c,v 1.72 2008/02/17 13:26:42 alex Exp $";
-
 /**
  * @file
  * IRC command parser and validator.
@@ -341,12 +338,25 @@ Validate_Command( UNUSED CONN_ID Idx, UNUSED REQUEST *Req, bool *Closed )
 
 
 static bool
-Validate_Args( UNUSED CONN_ID Idx, UNUSED REQUEST *Req, bool *Closed )
+Validate_Args(CONN_ID Idx, REQUEST *Req, bool *Closed)
 {
+       int i;
+
        assert( Idx >= 0 );
        assert( Req != NULL );
        *Closed = false;
 
+       for (i = 0; i < Req->argc; i++) {
+               if (strchr(Req->argv[i], '\r') || strchr(Req->argv[i], '\n')) {
+                       Log(LOG_ERR,
+                           "Invalid character(s) in parameter (connection %d, command %s)!?",
+                           Idx, Req->command);
+                       if (!Conn_WriteStr(Idx,
+                                          "ERROR :Invalid character(s) in parameter!"))
+                               *Closed = true;
+                       return false;
+               }
+       }
        return true;
 } /* Validate_Args */