KL-001-2020-006 : Barco wePresent Authentication Bypass  
Title: Barco wePresent Authentication Bypass  
Advisory ID: KL-001-2020-006  
Publication Date: 2020.11.20  
Publication URL:  
1. Vulnerability Details  
Affected Vendor: Barco  
Affected Product: wePresent WiPG-1600W  
Affected Version:  
Platform: Embedded Linux  
CWE Classification: CWE-288: Authentication Bypass Using an Alternate Path or Channel  
CVE ID: CVE-2020-28333  
2. Vulnerability Description  
The Barco wePresent web interface does not use session cookies  
for tracking authenticated sessions. Instead, the web interface  
uses a "SEID" token that is appended to the end of URLs in GET  
requests. Thus the "SEID" would be exposed in web proxy logs  
and browser history. An attacker that is able to capture the  
"SEID" and originate requests from the same IP address (via  
a NAT device or web proxy) would be able to access the user  
interface of the device without having to know the credentials.  
3. Technical Description  
In order to make configuration changes to the Barco wePresent  
WiPG-1600W, a "random" value sent to the web interface client  
from the device is required to be provided -- the "SEID". It  
seems to be acting like a Session ID in a cookie. However,  
the "SEID" is passed as a parameter in URLs and in the body  
of POSTs. Since it is passed as a parameter in the URL, it  
can be logged by web proxies or browser history. An example is:  
Where "ertqVvnKV4TjU9Vt" is the SEID. No session cookie exists,  
just this value passed on the URL as a parameter, and in the  
body of POSTs to make configuration changes. This SEID is all  
that is required to access pages behind authentication or to  
make configuration changes via POSTs. There is no Authorization  
header passed in the HTTP requests.  
4. Mitigation and Remediation Recommendation  
The vendor has released an updated firmware ( which  
remediates the described vulnerability. Firmware and release  
notes are available at:  
5. Credit  
This vulnerability was discovered by Jim Becher (@jimbecher) of  
KoreLogic, Inc.  
6. Disclosure Timeline  
2020.08.24 - KoreLogic submits vulnerability details to  
2020.08.25 - Barco acknowledges receipt and the intention  
to investigate.  
2020.09.21 - Barco notifies KoreLogic that this issue,  
along with several others reported by KoreLogic,  
will require more than the standard 45 business  
day remediation timeline. Barco requests to delay  
coordinated disclosure until 2020.12.11.  
2020.09.23 - KoreLogic agrees to 2020.12.11 coordinated disclosure.  
2020.09.25 - Barco informs KoreLogic of their intent to acquire  
CVE number for this vulnerability.  
2020.11.09 - Barco shares CVE number with KoreLogic and announces  
their intention to release the updated firmware  
ahead of schedule, on 2020.11.11. Request that KoreLogic  
delay public disclosure until 2020.11.20.  
2020.11.11 - Barco firmware release.  
2020.11.20 - KoreLogic public disclosure.  
7. Proof of Concept  
See section (3) Technical Description.  
The contents of this advisory are copyright(c) 2020  
KoreLogic, Inc. and are licensed under a Creative Commons  
Attribution Share-Alike 4.0 (United States) License:  
KoreLogic, Inc. is a founder-owned and operated company with a  
proven track record of providing security services to entities  
ranging from Fortune 500 to small and mid-sized companies. We  
are a highly skilled team of senior security consultants doing  
by-hand security assessments for the most important networks in  
the U.S. and around the world. We are also developers of various  
tools and resources aimed at helping the security community.  
Our public vulnerability disclosure policy is available at: