So cunning you could brush your teeth with it.

Wednesday, 8 October 2008

Lets take a look at a new tool available to Lenny & Sid:

apt-get source acon
int main(int argc,char **argv)
{
        int i,tty,useunicode=0;
        char *fontf=0,*translationf=0,*keymapf=0;

        get_ids();
        set_user_id();

        /*Read configure file if no input options*/
        if(argc<2)
        {
                char *env;
                FILE *fp;
                char font[300],translation[300],keymap[300];
                char tmp[300];

                font[0]=translation[0]=keymap[0]=0;
                if((env=getenv("HOME")))
                        sprintf(tmp,"%s/.acon.conf",env);
                else
                        strcpy(tmp,"/etc/acon.conf");

Hmmm. Nice use of the environment there. I wonder what permissions the binary has:

skx@gold:~$ ls -l /usr/bin/acon
-rwsr-xr-x 1 root root 48672 2008-06-09 10:50 /usr/bin/acon

setuid(0) - just say no.

ObTitle: Blackadder II

| 13 comments.

 

Comments On This Entry

[gravitar] Florian Weimer

Submitted at 22:53:51 on 6 october 2008

It's #475733 and supposedly fixed. I haven't looked at the package, though.
[gravitar] Des

Submitted at 22:56:03 on 6 october 2008

I don't get it, is this really the way to report this? I didn't find any bug#, and disclosing things like this... am I missing something?
[gravitar] Joe Buck

Submitted at 22:56:53 on 6 october 2008

Hope there's an RC bug for that one.
[author] Steve

Submitted at 23:20:53 on 6 october 2008

I saw the bug, but I'm scared of the code. e.g. the my_system call.

Still it does look like permissions are dropped prior to that being invoked.

[gravitar] brian m. carlson

Submitted at 04:12:43 on 7 october 2008

There was a call for an audit on debian-audit, and I audited the code. My recommendation to Moritz was that this code not be released due to the use of fixed-size buffers, magic constants, and unsafe functions (strcpy and sprintf). Apparently nobody listened. See #476603.
[gravitar] Helmut Grohne

Submitted at 06:59:30 on 7 october 2008

Have you seen http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=475733 or did it happen again?
Helmut
[gravitar] nion

Submitted at 12:58:56 on 7 october 2008

C'mon Steve, this blog post is really not fair, there is a) a bug for that and b) you didn't see debian/patches/05-CVE-2008-1994.diff did you? :)
[author] Steve Kemp

Submitted at 14:05:02 on 7 october 2008

Nion you're probably right.

I was updating my list of Setuid/setgid binaries in the archive and this package contained one near the top of the list. (Full list on gluck in ~skx/).

I started being shocked at the code. Then I saw the CVE assignment and rememembered we'd had a discussion.

I personally believe this package:

  • SHouldn't have ever been accepted into the archive.
  • Shouldn't be in Lenny.

I know that there were patches, but the application as a whole is not written in a secure fashion - and to require setuid(0) privileges just makes me scared.

[gravitar] rjc

Submitted at 12:34:50 on 8 october 2008

Seeing this and the last OpenSSL-related problems, one thing comes to my mind - OpenBSD-style code audit.
[gravitar] Jon

Submitted at 17:45:15 on 8 october 2008

rjc: well, in this case, the code *was* audited, sufficiently enough for the auditor to decide the code was not suitable for the OS. What is needed is perhaps for existing audits to be paid attention to?
[gravitar] Thomas

Submitted at 20:38:02 on 8 october 2008

The package has been removed by the request of the maintainer by now. Mind you: This package did provide a unique feature to Debian even if it is too bad to have in Debian. Luckily, a better-designed alternative seems to be available but it still needs some work.
[gravitar] James

Submitted at 05:34:57 on 9 october 2008

Why does this post keep going to the top of Planet Debian?
[author] Steve Kemp

Submitted at 06:34:46 on 9 october 2008

I failed to add a date to this entry, so each time I rebuilt the blog (to add the comments), it was marked as "new".

Thanks for pointing it out to me, I've fixed it now.

 

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