Apache mod_tcl is a TCL interpreting module for the Apache 2.x web server.
Sparfell discovered format string errors in calls to the set_var function in tcl_cmds.c and tcl_core.c.
A remote attacker could exploit the vulnerability to execute arbitrary code with the rights of the user running the Apache server.
There is no known workaround at this time.
All mod_tcl users should upgrade to the latest version:
# emerge --sync
# emerge --ask --oneshot --verbose ">=www-apache/mod_tcl-1.0.1"