Re: [H-BUGTRAQ] Critical Security Problem in 4.4BSD crt0

[brucec () HUMBUG ORG AU (A Bruce in the land of the Bruces)]

On Sun, 2 Feb 1997, Thomas H. Ptacek wrote:

> There is a critically important security problem in FreeBSD 2.1.5's C
> runtime support library that will enable anyone with control of the
> environment of a process to cause it to execute arbitrary code. All
> executable SUID programs on the system are vulnerable to this problem.
>
> On FreeBSD 2.1.5, startup locale processing is enabled by setting the
> environment variable "ENABLE_STARTUP_LOCALE". "startup_setrunelocale()" is
> called if the environment variable "LC_CTYPE" is set as well.

Quick fix (for shell users), 'declare -r' all suspect environment
variables to safe values in the system startup files for the shell.

--==--
Bruce.

A cynic is a person searching for an honest man, with a stolen lantern.
                -- Edgar A. Shoaff