Insecure temporary file and stack buffer overflow

[Dan Rosenberg]

Binary package hint: ettercap

The GTK version of ettercap uses a global settings file at /tmp/.ettercap_gtk and does not verify ownership of this file. When parsing this file for settings in gtkui_conf_read() (src/interfaces/gtk/ec_gtk_conf.c), an unchecked sscanf() call allows a maliciously placed settings file to overflow a statically-sized buffer on the stack. Stack-smashing protection catches it, but it still should be fixed.

Verify with:
$ perl -e 'print "A"x500' > /tmp/.ettercap_gtk && ettercap -G

Firstly, the settings file should not be globally accessible without checking ownership, which still gets hairy because an attacker could create a symlink or hard link to a victim-controlled file (unless you're using YAMA :p). The best thing would probably be to keep this file in the user's home directory instead.

Secondly, parsing configuration files should be robust against malformed input and not susceptible to trivial buffer overflows.

[Timothy Redaelli (timothy-redaelli)]

Fixed in my git => https://github.com/drizztbsd/ettercap/commit/7f8a7a8cc18fd852c795f3f531d98ca8b58f5cbc

[Gianfranco Costamagna (costamagnagianfranco)]

Fix Released in oneiric