TippingPoint Zero Day Initiative

Icon Labs Iconfidant SSL Server Key Length Remote Code Execution Vulnerability

ZDI-11-021: January 20th, 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 8034. For further product information on the TippingPoint IPS:

Vulnerability Details

This vulnerability allows remote attackers to execute arbitrary code on vulnerable installations of Icon Labs Iconfidant SSL Server. Authentication is not required to exploit this vulnerability.

The specific flaw exists in the functionality responsible for key exchange. If the sum of specific length fields within a client master key packet exceeds 0x4000, a static buffer can be overflowed leading to arbitrary code execution on the affected system.

Vendor Response

Icon Labs states:

Icon Labs states that this issue was first fixed in Iconfidant SSL 1.3.0 and recommends upgrading to Iconfidant 1.3.1. Please contact Icon Labs at support@icon-labs.com to update the latest Iconfidant SSL software.
"Icon Labs would like to thank an Anonymous researcher and TippingPoint's Zero Day Initiative for responsibly reporting this vulnerability, ZDI-CAN-403."

Disclosure Timeline

    2008-10-28 - Vulnerability reported to vendor
    2011-01-20 - Coordinated public release of advisory


This vulnerability was discovered by: