ZDI-11-155: Sybase M-Business Anywhere Server agd.exe encodeUsername Remote Code Execution Vulnerability

http://www.zerodayinitiative.com/advisories/ZDI-11-155

May 9, 2011

-- CVSS:
10, (AV:N/AC:L/Au:N/C:C/I:C/A:C)

-- Affected Vendors:
Sybase

-- Affected Products:
Sybase MBusiness Anywhere

-- TippingPoint(TM) IPS Customer Protection:
TippingPoint IPS customers have been protected against this
vulnerability by Digital Vaccine protection filter ID 10911. 
For further product information on the TippingPoint IPS, visit:

    http://www.tippingpoint.com

-- Vulnerability Details:
This vulnerability allows remote attackers to execute arbitrary code on
vulnerable installations of Sybase MBusiness Anywhere. Authentication is
not required to exploit this vulnerability. 

The flaw exists within the agd.exe component which listens by default on
TCP port 80 and 443. When calling agd!encodeUsername the process creates
a 100 byte buffer on the heap. The process then blindly copies user
supplied data into that fixed-length buffer without verifying that the
size of the destination buffer is adequately sized. A remote attacker
can exploit this vulnerability to execute arbitrary code under the
context of the SYSTEM user.

-- Vendor Response:
Sybase has issued an update to correct this vulnerability. More
details can be found at:

http://www.sybase.com/detail?id=1093029

-- Disclosure Timeline:
2011-01-20 - Vulnerability reported to vendor
2011-05-09 - Coordinated public release of advisory

-- Credit:
This vulnerability was discovered by:
    * AbdulAziz Hariri

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