Trustwave SpiderLabs Security Advisory TWSL2018-010:
Credential Leak Flaws in Windows PureVPN Client

Published: 10/29/2018 
Version: 1.1

Vendor: PureVPN (https://www.purevpn.com)
Product: PureVPN Windows Client
Version affected:  prior to 6.1.0

Product description:
Windows version of the PureVPN client.

Finding 1: Plaintext storage of PureVPN Windows Client Credentials
Credit: Manuel Nader of Trustwave
CVE: CVE-2018-18656

The PureVPN Windows Client stores the Login Credentials (username and password)
in plaintext. The location of the file is: 'C:\ProgramData\purevpn\config\login.conf'

Additionally, such file has can be read by all local users in a multiuser environment.

Finding 2: Local attacker may obtain another user's PureVPN Credentials
Credit: Manuel Nader of Trustwave 

The PureVPN Windows Client provided by PureVPN may allow a local attacker to
retrieve the stored password of the last user who successfully logged in to the
PureVPN service. A local attacker may obtain another user's PureVPN credentials
when a Windows machine has multiple users, if they have successfully logged in.
The attack is done exclusively through the GUI (Graphical User Interface),
there's no need to use an external tool.

Steps to obtain the password:
1. Open the PureVPN Windows Client.
2. Go to Configuration
3. Open the "User Profile" tab
4. Click on "Show Password"

Remediation Steps:
Upgrade to the latest stable version of PureVPN.  Please note that Trustwave
confirmed PureVPN mitigated plaintext password storage in version 6.1.0. The
vender has accepted the risks of the password being revealed in the client's
configuration window.  Additionally, it is recommended to never re-use passwords and
enable two-factor authentication when possible.

Revision History:
08/17/2017 - Vulnerability disclosed to vendor
06/25/2018 - Patch released by vendor
09/27/2018 - Advisory version 1.0 published
10/26/2018 - CVE assigned
10/29/2018 - Advisory version 1.1 published

About Trustwave:
Trustwave helps businesses fight cybercrime, protect data and reduce security 
risk. With cloud and managed security services, integrated technologies and a 
team of security experts, ethical hackers and researchers, Trustwave enables 
businesses to transform the way they manage their information security and 
compliance programs. More than three million businesses are enrolled in the 
Trustwave TrustKeeper® cloud platform, through which Trustwave delivers 
automated, efficient and cost-effective threat, vulnerability and compliance 
management. Trustwave is headquartered in Chicago, with customers in 96 
countries. For more information about Trustwave, visit 
https://www.trustwave.com.

About Trustwave SpiderLabs:
SpiderLabs(R) is the advanced security team at Trustwave focused on
application security, incident response, penetration testing, physical
security and security research. The team has performed over a thousand
incident investigations, thousands of penetration tests and hundreds of
application security tests globally. In addition, the SpiderLabs Research
team provides intelligence through bleeding-edge research and proof of
concept tool development to enhance Trustwave's products and services.
https://www.trustwave.com/spiderlabs

Disclaimer:
The information provided in this advisory is provided "as is" without
warranty of any kind. Trustwave disclaims all warranties, either express or
implied, including the warranties of merchantability and fitness for a
particular purpose. In no event shall Trustwave or its suppliers be liable
for any damages whatsoever including direct, indirect, incidental,
consequential, loss of business profits or special damages, even if
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