Bugzilla Bug 74478

Advisory from securesoftware@list.cr.yp.to:

Date: 15 Dec 2004 08:29:07 -0000
From: "D. J. Bernstein" <djb@cr.yp.to>
Subject: [remote] [control] o3read 0.0.3 parse_html overflows t buffer
To: securesoftware@list.cr.yp.to, o3read@siag.nu
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Wiktor Kopec, a student in my Fall 2004 UNIX Security Holes course, has
discovered a remotely exploitable security hole in o3read, a converter
for SXW files. I'm publishing this notice, but all the discovery credits
should be assigned to Kopec.

You are at risk if you take an SXW document from an email message (or a
web page or any other source that could be controlled by an attacker)
and feed it through o3read. (The o3read documentation does not tell
users to avoid taking input from the network.) Whoever provides that
document then has complete control over your account: he can read and
modify your files, watch the programs you're running, etc.

Proof of concept: On an x86 computer running FreeBSD 4.10, type

   wget ftp://siag.nu/pub/o3read/o3read-0.0.3.tar.gz
   gunzip < o3read-0.0.3.tar.gz | tar -xf -
   cd o3read-0.0.3
   make

to download and compile the o3read program, version 0.0.3 (current).
Then save the file 58.xml attached to this message, and type

   ./o3read < 58.xml

with the unauthorized result that a file named x is removed from the
current directory. (I tested this with a 535-byte environment, as
reported by printenv | wc -c.)

Here's the bug: In o3read.c, parse_html copies any number of bytes into
a 1024-byte t[] array.

---D. J. Bernstein, Associate Professor, Department of Mathematics,
Statistics, and Computer Science, University of Illinois at Chicago

Created an attachment (id=46030) [details]
58.xml from advisory

======================================================
Candidate: CAN-2004-1288
URL: http://cve.mitre.org/cgi-bin/cvename.cgi?name=CAN-2004-1288
Reference: MISC:http://tigger.uic.edu/~jlongs2/holes/o3read.txt

Buffer overflow in the parse_html function in o3read.c for o3read
0.0.3 allows remote attackers to execute arbitrary code via a crafted
SXW file.
======================================================

Upstream looks dead. 0.0.3 version was released 26-Nov-2002.

Looks like a good candidate for security masking. Jon: please let us know if you think you can fix it or if you prefer that we mask it.

Download location is dead, it survives because it's been mirrored by us.
avenj did not answer, requesting a mask here too.

package masked by request of koon/security team.

Download location is now apparently up.  Version 0.0.4 released.  Only
ChangeLog notice is this:

050107  Added range check to parse_html().

Apart from a few comments and some extra stuff in the Makefile, this is the
only change.  An ebuild version bump compiles and installs correctly, but I
couldn't verify that the proof of concept code didn't work any more (couldn't
get it to work in the first place, since it's apparently BSD shell-code and I'm
using Linux).

Thanks Peter, did not notice that.
avenj: care to bump ?

Sorry about the delayed response; I get a very large quantity of mail from
Bugzilla, and it's easy for things to get lost.

I've committed o3read 0.0.4. This app is extremely trivial, and as such 0.0.4
has been committed directly to stable.

Thanks Jon, ready for a GLSA.
Package should be unmasked before sending.

Removed the mask.

GLSA 200501-20