Synopsis: Moderate: tcl security and bug fix update
Issue Date: 2013-01-08
CVE Numbers: CVE-2007-4772
Two denial of service flaws were found in the Tcl regular expression handling
engine. If Tcl or an application using Tcl processed a specially-crafted
regular expression, it would lead to excessive CPU and memory consumption.
This update also fixes the following bug:
* Due to a suboptimal implementation of threading in the current version of the
Tcl language interpreter, an attempt to use threads in combination with fork in
a Tcl script could cause the script to stop responding. At the moment, it is
not possible to rewrite the source code or drop support for threading entirely.
Consequent to this, this update provides a version of Tcl without threading
support in addition to the standard version with this support. Users who need
to use fork in their Tcl scripts and do not require threading can now switch to
the version without threading support by using the alternatives command.
– Scientific Linux Development Team