TippingPoint Zero Day Initiative

Unitronics UniDownloader IPWorksSSL.HTTPS.1 ActiveX Control SSLCertHandle Property Remote Code Execution Vulnerability

ZDI-15-575: December 2nd, 2015


CVSS Score

Affected Vendors

Affected Products


Vulnerability Details

This vulnerability allows remote attackers to execute arbitrary code on vulnerable installations of Unitronics UniDownloader. 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 processing of the SSLCertHandle property of the IPWorksSSL.HTTPS ActiveX control. A crafted value can cause system software to treat arbitrary memory as a certificate structure which is then modified. An attacker can leverage this to attain remote code execution under the context of the user.

Vendor Response

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

Disclosure Timeline

    2015-05-20 - Vulnerability reported to vendor
    2015-12-02 - Coordinated public release of advisory


This vulnerability was discovered by:
    Andrea Micalizzi (rgod)