full-disclosure - Re: GNU tar directory traversal

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <1164162659.5066.18.camel@8104>
Date: Wed, 22 Nov 2006 02:30:59 +0000
From: Gouki <Gouki@...kiHQ.org>
To: full-disclosure@...ts.grok.org.uk
Subject: Re: GNU tar directory traversal

Jeb, even so, I don't think 'LOLOLOLOL' is the best way to let Teemu
know that. I personally would not like this kind of attitude.

Don't take this the wrong way, I just didn't like this behavior on a
list like this.

Take care.

Regards,

Gouki

On Wed, 2006-11-22 at 07:45 +0530, Jeb Osama wrote:
> 
>         From: Teemu Salmela <teemu.salmela@....fi >
>         
>         
>         GNU tar directory traversal
>         ----------------------------------------------------------------------------
>         What is it?
>         When i download a tar file (warez.tar.gz in this example) from
>         the web and
>         run the following commands: 
>         
>         $ mkdir ~/warez
>         $ tar xzf warez.tar.gz -C ~/warez
>         
>         , then i would expect that tar doesn't create or replace any
>         files outside
>         the ~/warez directory. Today, i was browsing the GNU tar
>         source code trying 
>         to find a way to create/overwrite arbitrary files, and i found
>         it!
>         
>         Normal tar symlinks/hardlinks are handled correctly in GNU tar
>         (i think),
>         but there is one tar record type, called GNUTYPE_NAMES (this
>         is some kind 
>         of GNU extension, i think), that allows me to create symbolic
>         links
>         (inside the ~/warez directory, in this example) pointing to
>         arbitrary
>         locations in the filesystem. In the exploit, i make a sybolic
>         link called 
>         "xyz", pointing to "/". After that record, more records would
>         follow
>         that extract files to the "xyz" directory.
>         
>         Version numbers:
>         ---------------------------------------------------------------------------- 
>         I tested this on Ubuntu 6.06 LTS, GNU tar 1.16 and GNU tar
>         1.15.1 (this one
>         comes with Ubuntu)
>         
>         Vulnerable code:
>         ----------------------------------------------------------------------------
>         See extract_archive() in extract.c and extract_mangle() in
>         mangle.c.
>         
>         Exploit:
>         ----------------------------------------------------------------------------
>         [snip tEh C code]
>         --
>         fscanf(socket,"%s",buf); printf(buf);
>         sprintf(query, "SELECT %s FROM table", buf);
>         sprintf(cmd, "echo %s | sqlquery", query); system(cmd);
>         Teemu Salmela
>         
>         ----------------------------------------------------------------------------
> 
> LOLOLOLOLOLOLOLOLOL
> Thats pretty much the purpose of symlinks.. Whats your point in
> posting this fact in FD?
> 
> Jeb
> 
> 
> 
> _______________________________________________
> Full-Disclosure - We believe in it.
> Charter: http://lists.grok.org.uk/full-disclosure-charter.html
> Hosted and sponsored by Secunia - http://secunia.com/
-- 
*//=================================================================
  .-. Fingerprint: 4B36 0BC2 82CE 6858 4893 7132 BC98 A7E4 3482 BA17
  /v\  Size / Type: 1024/DSA
 // \\  Availability: MIT's PKS - pgp.mit.edu
/(   )\  Homepage: GoukiHQ.org
 ^^-^^    |PHEAR THE PENGUIN|
*//=================================================================

Download attachment "signature.asc" of type "application/pgp-signature" (192 bytes)

_______________________________________________
Full-Disclosure - We believe in it.
Charter: http://lists.grok.org.uk/full-disclosure-charter.html
Hosted and sponsored by Secunia - http://secunia.com/