Disable window title reporting by default, since it's a security

[u/mdw/putty] / doc / config.but

diff --git a/doc/config.but b/doc/config.but
index 300b9ef..fa70a09 100644 (file)
--- a/doc/config.but
+++ b/doc/config.but
@@ -1,4 +1,4 @@
-\versionid $Id: config.but,v 1.61 2003/04/11 17:39:48 simon Exp $
+\versionid $Id: config.but,v 1.62 2003/04/12 08:59:06 simon Exp $
 
 \C{config} Configuring PuTTY
 
@@ -776,6 +776,26 @@ commands from the server. If you find PuTTY is doing this
 unexpectedly or inconveniently, you can tell PuTTY not to respond to
 those server commands.
 
+\S{config-features-qtitle} Disabling remote window title querying
+
+\cfg{winhelp-topic}{features.qtitle}
+
+PuTTY can optionally provide the xterm service of allowing server
+applications to find out the local window title. This feature is
+disabled by default, but you can turn it on if you really want it.
+
+NOTE that this feature is a \e{potential security hazard}. If a
+malicious application can write data to your terminal (for example,
+if you merely \c{cat} a file owned by someone else on the server
+machine), it can change your window title (unless you have disabled
+this as mentioned in \k{config-features-retitle}) and then use this
+service to have the new window title sent back to the server as if
+typed at the keyboard. This allows an attacker to fake keypresses
+and potentially cause your server-side applications to do things you
+didn't want. Therefore this feature is disabled by default, and we
+recommend you do not turn it on unless you \e{really} know what you
+are doing.
+
 \S{config-features-dbackspace} Disabling destructive backspace
 
 \cfg{winhelp-topic}{features.dbackspace}