Follow @Openwall on Twitter for new release announcements and other news
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date: Tue, 1 Mar 2011 10:24:48 +0000
From: Helgi Þormar Þorbjörnsson <>
Cc: Dan Rosenberg <>,
 Pierre Joye <>
Subject: Re: CVE Request: PEAR Installer 1.9.1 <= - Symlink Attack

On 1 Mar 2011, at 09:11, Pierre Joye wrote:

> hi,
> 2011/2/28 Dan Rosenberg <>:
>> I'm not familiar with this code or any of the context surrounding this
>> fix, but it appears to be an incomplete fix.  Checking for existence
>> of a symlink and then opening the resource leaves open a window during
>> which a legitimate file can be replaced with a symlink.
> Not sure it is fixable, or maybe using a lock on the symbolic link
> while fetching its target (to be tested to be sure that such locks
> cannot be overridden from shell).

I assume you are referring to the parts for REST.php in the patch in question?
At a second look, that part could do with improvements; I wrote up a function which takes TOCTOU into consideration.
I'll have that patch done by the end of the day.

For other situations I am using tempnam() (via the System class) as those files are only temporary and were being extracted from compressed archives; The predictability of their end destination where the centre part of the reported security problem.

- Helgi

Powered by blists - more mailing lists

Please check out the Open Source Software Security Wiki, which is counterpart to this mailing list.

Confused about mailing lists and their use? Read about mailing lists on Wikipedia and check out these guidelines on proper formatting of your messages.