Package: xvnc4viewer Version: 4.1.1+X4.3.0-30 Severity: normal Tags: patch When reading server host and number from stdin, xvnc4viewer does not check whether anything was entered at all. When the user just presses C-d or fgets() sees End-Of-File for some other reason, it will leave the buffer it should read the line into uninitialized, which means that getHostAndPort() is called with an uninitialized string which can't be good.
Also, if the user somehow gives a line without trailing newline to xvnc4viewer
when it read server host and number, xvnc4viewer will chop of the last
character of the server specification. So lets check whether the last
character actually is '\n' first.
Bye,
Jö.
======================================================================
diff -ru vnc4-4.1.1+X4.3.0_orig/unix/vncviewer/CConn.cxx
vnc4-4.1.1+X4.3.0/unix/vncviewer/CConn.cxx
--- vnc4-4.1.1+X4.3.0_orig/unix/vncviewer/CConn.cxx 2008-12-27
22:32:48.000000000 +0100
+++ vnc4-4.1.1+X4.3.0/unix/vncviewer/CConn.cxx 2008-12-27 22:28:37.000000000
+0100
@@ -93,9 +93,15 @@
/* Get server */
fprintf(stderr, "Server: ");
vncServerName = new char[128];
- fgets(vncServerName, 128, stdin);
- /* remove \n at the end */
- vncServerName[strlen(vncServerName)-1] = '\0';
+ if(fgets(vncServerName, 128, stdin)) {
+ size_t len = strlen(vncServerName);
+ /* remove \n at the end */
+ if(vncServerName[len-1] == '\n')
+ vncServerName[len-1] = '\0';
+ } else {
+ /* fgets failed, probably eof -- assume empty string as input */
+ vncServerName[0] = '\0';
+ }
getHostAndPort(vncServerName, &serverHost, &serverPort);
} else {
ServerDialog dlg(dpy, &options, &about);
======================================================================
-- System Information:
Debian Release: 5.0
APT prefers testing-proposed-updates
APT policy: (500, 'testing-proposed-updates'), (500, 'testing')
Architecture: i386 (i686)
Kernel: Linux 2.6.26-1-686 (SMP w/2 CPU cores)
Locale: LANG=de_DE.UTF-8, LC_CTYPE=de_DE.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/bash
Versions of packages xvnc4viewer depends on:
ii libc6 2.7-16 GNU C Library: Shared libraries
ii libgcc1 1:4.3.2-1 GCC support library
ii libice6 2:1.0.4-1 X11 Inter-Client Exchange library
ii libsm6 2:1.0.3-2 X11 Session Management library
ii libstdc++6 4.3.2-1 The GNU Standard C++ Library v3
ii libx11-6 2:1.1.5-2 X11 client-side library
ii libxext6 2:1.0.4-1 X11 miscellaneous extension librar
ii zlib1g 1:1.2.3.3.dfsg-12 compression library - runtime
xvnc4viewer recommends no packages.
xvnc4viewer suggests no packages.
-- no debconf information
--
Computers are like air conditioners. Both stop working, if you open
windows.
-- Adam Heath
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