Follow @Openwall on Twitter for new release announcements and other news
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date: Thu, 28 Jul 2016 06:31:20 -0700
From: lazytyped <>
Subject: Re: Re: Use after free in my_login() function of
 DBD::mysql (Perl module)

On 7/26/16 6:32 PM, wrote:
> Hash: SHA256
>> DBD::mysql versions 4.033 and earlier have a use after free bug in the
>> my_login() function. DBD::mysql is a Perl module providing bindings to
>> the mysql database. The issue was fixed in version 4.034.
>>> When my_login fails the code tries to call mysql_errno on the mysql
>>> connection. However my_login has already free'd that connection
>>> variable, therefore causing a use-after-free error.
>>> This patch changes that so that the free happens after the call to the
>>> error functions.
> Use CVE-2015-8949.

Quick question:

- I guess the affecting function call is the following:

   do_error(dbh, mysql_errno(imp_dbh->pmysql),

which one of those calls provides an exploitation path? They seem all 
reads off the free'd structure.

I see in the bug report: " (I think use after free's can be serious and 
potentially lead to malfunction and security issues)" and would like to 
understand more about the rationale.

            -  twiz

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.