Full Disclosure mailing list archives

Re: Predefined Post Authentication Session ID Vulnerability


From: Benji <me () b3nji com>
Date: Fri, 13 Jul 2012 10:49:06 +0100

Yes, god Jann, you're such a moron.

On Fri, Jul 13, 2012 at 9:46 AM, Gokhan Muharremoglu
<gokhan.muharremoglu () iosec org> wrote:
You can find an example page and combined vulnerabilities below URL.
This example login page is affected by Predefined Post Authentication
Session ID Vulnerability.
This vulnerability can lead a social engineering scenario or other hijacking
attack scenarios when mixed with other vulnerabilities (such XSS).

For proof of concept:

http://www.iosec.org/iosec_login_vulnerable.php


Predefined Post Authentication Session ID Vulnerability is a Vendor-neutral
vulnerability and it let attackers to design new attack scenarios.
A lot of web application on the Internet affected by this vulnerability.

-----------------------
Vulnerability Name: Predefined Post Authentication Session ID Vulnerability
Type: Improper Session Handling
Impact: Session Hijacking
Level: Medium
Date: 10.07.2012
Vendor: Vendor-neutral
Issuer: Gokhan Muharremoglu
E-mail: gokhan.muharremoglu () iosec org


VULNERABILITY
If a web application starts a session and defines a session id before a user
authenticated, this session id must be changed after a successful
authentication. If web application uses the same session id before and after
authentication, any legitimate user who has gained the "before
authentication" session id can hijack future "after authentication" sessions
too.

MITIGATION
To avoid this vulnerability, sessions must be regenerated after a successful
login. In a session fixation attack, attacker fixates (sets) another
person's (victim's) session identifier because of "never regenerated and
validated" session id and this vulnerability can also lead to the Session
Fixation attack or etc.

Gokhan Muharremoglu
Information Security Specialist
(CEH, ECSA, CIW-Web Security Professional, Security+, EXIN 27002 ISFS)

-----Original Message-----
From: Jann Horn [mailto:jannhorn () googlemail com]
Sent: Friday, July 13, 2012 2:06 AM
To: Gokhan Muharremoglu
Cc: full-disclosure () lists grok org uk
Subject: Re: [Full-disclosure] Predefined Post Authentication Session ID
Vulnerability

On Wed, Jul 11, 2012 at 11:34:11AM +0300, Gokhan Muharremoglu wrote:
Vulnerability Name: Predefined Post Authentication Session ID
Vulnerability
Type: Improper Session Handling
Impact: Session Hijacking
Level: Medium
Date: 10.07.2012
Vendor: Vendor-neutral
Issuer: Gokhan Muharremoglu
E-mail: gokhan.muharremoglu () iosec org


VULNERABILITY
If a web application starts a session and defines a session id before
a user authenticated, this session id must be changed after a
successful authentication. If web application uses the same session id
before and after authentication, any legitimate user who has gained
the "before authentication" session id can hijack future "after
authentication" sessions too.

Uh, so, erm, you assume that someone can steal my cookie/set it/whatever
although the Same Origin Policy should clearly not allow that, and then,
after I have logged in, he can't just steal my cookie? Unless you allow
setting the session-ID via an URL or so (which would IMO be pretty stupid),
I can't see how this is a realistic, vendor-neutral attack. Could you
explain this a bit better? I don't get it.

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_______________________________________________
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Charter: http://lists.grok.org.uk/full-disclosure-charter.html
Hosted and sponsored by Secunia - http://secunia.com/


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