Exponent CMS 2.6.0 patch2 - Stored XSS (User-Agent)

5.4

Medium

Discovered by 

Oscar Uribe

Offensive Team, Fluid Attacks

Summary

Full name

Exponent CMS 2.6.0 patch2 - Stored XSS (User-Agent)

Code name

State

Public

Release date

Feb 3, 2022

Affected product

Exponent CMS

Affected version(s)

v2.6.0 patch2

Vulnerability name

Stored cross-site scripting (XSS)

Remotely exploitable

Yes

CVSS v3.1 vector string

CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N

CVSS v3.1 base score

5.4

Exploit available

No

Description

Exponent CMS 2.6.0 patch2 allows an authenticated user to inject persistent javascript code on the User-Agent when logging in. When an administratoruser visits the 'User Sessions' tab, the javascript will be triggered allowingan attacker to compromise the administrator session.

Proof of Concept

  1. Use a Web proxy or a tool to modify the browser User-agent with the following PoC.

    User-Agent: <script>alert('XSS')</script>
  2. Try to login with a non-admin user.

  3. If an admin user visits 'User Management' > 'User Sessions' the XSS will be triggered.

A non-admin user may compromise an admin session by exploiting this vulnerability.

System Information:

  • Version: Exponent CMS 2.6.0 patch2.

  • Operating System: Linux.

  • Web Server: Apache

  • PHP Version: 7.4

  • Database and version: Mysql

Exploit

There is no exploit for the vulnerability but can be manually exploited.

Mitigation

By 2022-02-03 there is not a patch resolving the issue.

References

Timeline

Vulnerability discovered

Jan 25, 2022

Vendor contacted

Jan 25, 2022

Public disclosure

Feb 3, 2022

Start your 21-day free trial

Discover the benefits of our Continuous Hacking solution, which organizations of all sizes are already enjoying.

Start your 21-day free trial

Discover the benefits of our Continuous Hacking solution, which organizations of all sizes are already enjoying.

Start your 21-day free trial

Discover the benefits of our Continuous Hacking solution, which organizations of all sizes are already enjoying.

Fluid Attacks' solutions enable organizations to identify, prioritize, and remediate vulnerabilities in their software throughout the SDLC. Supported by AI, automated tools, and pentesters, Fluid Attacks accelerates companies' risk exposure mitigation and strengthens their cybersecurity posture.

SOC 2 Type II

SOC 3

Subscribe to our newsletter

Stay updated on our upcoming events and latest blog posts, advisories and other engaging resources.

© 2025 Fluid Attacks. We hack your software.

Fluid Attacks' solutions enable organizations to identify, prioritize, and remediate vulnerabilities in their software throughout the SDLC. Supported by AI, automated tools, and pentesters, Fluid Attacks accelerates companies' risk exposure mitigation and strengthens their cybersecurity posture.

SOC 2 Type II

SOC 3

Subscribe to our newsletter

Stay updated on our upcoming events and latest blog posts, advisories and other engaging resources.

© 2025 Fluid Attacks. We hack your software.

Fluid Attacks' solutions enable organizations to identify, prioritize, and remediate vulnerabilities in their software throughout the SDLC. Supported by AI, automated tools, and pentesters, Fluid Attacks accelerates companies' risk exposure mitigation and strengthens their cybersecurity posture.

SOC 2 Type II

SOC 3

Subscribe to our newsletter

Stay updated on our upcoming events and latest blog posts, advisories and other engaging resources.

© 2025 Fluid Attacks. We hack your software.