TippingPoint Zero Day Initiative

RealNetworks RealPlayer SWF DefineFont Remote Code Execution Vulnerability

ZDI-11-268: August 16th, 2011


CVSS Score

Affected Vendors

Affected Products

TippingPoint™ IPS Customer Protection

TippingPoint IPS customers are protected against this vulnerability by Digital Vaccine protection filter ID 11351. For further product information on the TippingPoint IPS:

Vulnerability Details

This vulnerability allows remote attackers to execute arbitrary code on vulnerable installations of RealNetworks RealPlayer. User interaction is required to exploit this vulnerability in that the target must visit a malicious page or open a malicious file.

The specific flaw exists within the way RealPlayer handles DEFINEFONT fields in Flash Files. When the process parses corrupt a ShapeRecord with the DefineFont record it reads outside a stack buffer and uses a random stack value as a heap pointer. Later this pointer will be used to write data into. The resulting corruption can lead to remote code execution under the context of the current user.

Vendor Response

RealNetworks has issued an update to correct this vulnerability. More details can be found at:

Disclosure Timeline

    2011-04-01 - Vulnerability reported to vendor
    2011-08-16 - Coordinated public release of advisory


This vulnerability was discovered by:
    Luigi Auriemma