ActiveTcl CVE-2012-5378 Insecure File Permissions Vulnerability

Posted by grahams on 2012-10-25 13:59
OS: Windows | Product: ActiveTcl | tags: advisory CVE Security

We have read the Security alert for CVE-2012-5378, and would like more information.


This is not a new issue, and it's not really an ActiveTcl issue. This vulnerability is a member of a class of vulnerabilities that apply to any software which needs to have a user-writable directory on $PATH. It has been a security concern on Windows for as long as software has been avoiding dll conflicts by using custom library paths.

It is already possible to mitigate the vulnerability by choosing to override the default install path and install to one of the various protected program files silos that newer versions of Windows offer. We don't do this as the default because ActiveTcl has a long legacy of scripts and modules which do not handle spaces in the pathname.

It is also possible to migate the vulnerability on an inplace install. This powershell script will copy the permissions to the Tcl directory (replace with your directory name, as installed):

powershell -command "(Get-Item 'C:\Program Files').GetAccessControl('Access') | set-acl 'C:\Tcl'"

Be advised that protecting Tcl from this vulnerability *will* result in reduced functionality. With altered acls, teacup will be unable to manage modules unless it is run with elevated priviledges.

Powershell is included in Windows 7. With older versions, you may be able to download.