# MA-610.052016: MyCERT Alert - WPAD Name Collision Vulnerability

**Date:** 25 May 2016  
**Source:** https://www.mycert.org.my/portal/advisory?id=MA-610.052016  
**Advisory ID:** MA-610.052016

---

####
**1.0 Introduction**
WPAD is a protocol used to ensure all systems in an organization utilize the same web proxy configuration. Instead of individually modifying configurations on each device connected to a network, WPAD locates a proxy configuration file and applies the configuration automatically.
The use of WPAD is enabled by default on all Microsoft Windows operating systems and Internet Explorer browsers. WPAD is supported but not enabled by default on Mac and Linux-based operating systems, as well as, Safari, Chrome, and Firefox browsers..
Web Proxy Auto-Discovery (WPAD) Domain Name System (DNS) queries that are intended for resolution on private or enterprise DNS servers have been observed reaching public DNS servers. In combination with the New generic Top Level Domain (gTLD) program’s incorporation of previously undelegated gTLDs for public registration, leaked WPAD queries could result in domain name collisions with internal network naming schemes.
Users and administrators are encouraged to provide a more secure and efficient network infrastructure by following the recommendations.
**2.0 Impact**
The exploitation of this leaked WPAD queries could result in domain name collisions with internal network naming schemes. If an attacker registers a domain to answer leaked WPAD queries and configures a valid proxy, there is potential to conduct man-in-the-middle (MitM) attacks across the Internet.
**3.0 Affected Products**
The affected systems are:
- Windows,
- OS X,
- Linux systems,
- Web browsers with WPAD enabled,
- Networks using unregistered or unreserved TLDs
**4.0 Recommendation**
MyCERT highly recommends users and network administrators to implement the following recommendations to provide a more secure and efficient network infrastructure:
> 4.1 Consider disabling automatic proxy discovery/configuration in browsers and operating systems during device setup if it will not be used for internal networks.
>
> 4.2 Consider using a fully qualified domain name (FQDN) from global DNS as the root for enterprise and other internal namespace.
>
> 4.3 Configure internal DNS servers to respond authoritatively to internal TLD queries.
>
> 4.4 Configure firewalls and proxies to log and block outbound requests for wpad.dat files.
>
> 4.5 Identify expected WPAD network traffic and monitor the public namespace or consider registering domains defensively to avoid future name collisions.
>
> 4.6 File a report with ICANN if your system is suffering demonstrably severe harm as a consequence of name collision by visiting <https://forms.icann.org/en/help/name-collision/report-problems>
Generally, MyCERT advises the users of this software to be updated with the latest security announcements by the vendor and follow best practice security policies to determine which updates should be applied.
For further enquiries, please contact MyCERT through the following channels:
E-mail: [[email protected]](/cdn-cgi/l/email-protection#8ceff5eee9feb5b5b5cceff5eee9feffe9eff9fee5f8f5a2e1f5) or [[email protected]](/cdn-cgi/l/email-protection#f994809a9c8b8db994809a9c8b8dd7968b9ed79480) 
Phone: 1-300-88-2999 (monitored during business hours)
Fax: +603 89453442 
Mobile: +60 19 2665850 (24x7 call incident reporting)
SMS : CYBER999 REPORT EMAIL COMPLAINT to 15888
Business Hours : Mon - Fri 09:00 AM - 18:00 PM MYT
Web: [https://www.mycert.org.my](https://www.mycert.org.my/)
Twitter: <http://www.twitter.com/mycert>
Cyber999 Mobile Apps: [IOS Users](https://itunes.apple.com/my/app/cyber999-mobile-application/id888552400?mt=8&ign-mpt=uo%3D4) or [Android Users](https://play.google.com/store/apps/details?id=my.cyber999.mobile)
**5.0 References**
- WPAD Name Collision Vulnerability: <https://www.us-cert.gov/ncas/alerts/TA16-144A>
- Web Proxy Auto-Discovery Access privileged data: <https://www.auscert.org.au/render.html?it=34930>
- Enterprise Remediation For Wpad Name Collision Vulnerability: <http://www.verisign.com/assets/Enterprise_Remediation_for_WPAD_Name_Collision_Vulnerability.pdf>