Quoting http://www.securityfocus.com/bid/18642

  Mutt is prone to a remote buffer-overflow vulnerability. This
  issue is due to the application's failure to properly bounds-check
  user-supplied input before copying it to an insufficiently sized
  memory buffer.

  This issue may allow remote attackers to execute arbitrary machine
  code in the context of the affected application. Failed exploit
  attempts will likely crash the application, denying further service to
  legitimate users.

  Mutt version 1.4.2.1 is reported to be vulnerable. Other versions may
  be affected as well.

Fix: 

The following is a patch taken from the mutt source repository, and
minimally adapted to work with the ports framework. Afterward, mutt
runs. I have verified neither the problem nor whether this fixes it.

From: brendan <brendan>
Date: Mon, 19 Jun 2006 18:14:03 +0000 (+0000)
Subject: From: TAKAHASHI Tamotsu <tamo@momonga-linux.org>
X-Git-Url: http://dev.mutt.org/cgi-bin/gitweb.cgi?p=mutt/.git;a=commitdiff;h=dc0272b749f0e2b102973b7ac43dbd3908507540

  From: TAKAHASHI Tamotsu <tamo@momonga-linux.org>
  
  Fix browse_get_namespace() which could overflow ns[LONG_STRING].
  (Possible remote vulnerability)
---

--- imap/browse.c.orig
+++ imap/browse.c
@@ -505,7 +505,7 @@ static int browse_get_namespace (IMAP_DA
 	    if (*s == '\"')
 	    {
 	      s++;
-	      while (*s && *s != '\"') 
+	      while (*s && *s != '\"' && n < sizeof (ns) - 1) 
 	      {
 		if (*s == '\\')
 		  s++;
@@ -516,12 +516,14 @@ static int browse_get_namespace (IMAP_DA
 		s++;
 	    }
 	    else
-	      while (*s && !ISSPACE (*s)) 
+	      while (*s && !ISSPACE (*s) && n < sizeof (ns) - 1)
 	      {
 		ns[n++] = *s;
 		s++;
 	      }
 	    ns[n] = '\0';
+	    if (n == sizeof (ns) - 1)
+	      dprint (1, (debugfile, "browse_get_namespace: too long: [%s]\n", ns));
 	    /* delim? */
 	    s = imap_next_word (s);
 	    /* delimiter is meaningless if namespace is "". Why does