Testimonials Slider <= 3.5.8.3 - Authenticated (Editor+) Stored Cross-Site Scripting
Strategic Overview
- Status
- Patched in 3.5.8.4
- Affected Plugin
- Testimonial Slider – Free Testimonials Slider Plugin
- Affected Version
<= 3.5.8.3- CVSS
- 4.1Medium
- Weakness type
- CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
- CVE
CVE-2021-36851
At a glance
CVE-2021-36851 is a medium-severity Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in the Testimonial Slider WordPress plugin, affecting versions <= 3.5.8.3. It carries a CVSS score of 4.1 (reachable over the network; low attack complexity). Exploitation requires an authenticated account at Editor level or above. The issue is fixed in version 3.5.8.4; sites on affected versions should update now. Disclosed April 2022, reported by Ngo Van Thien.
Vulnerability Overview
Authenticated (editor or higher user role) Cross-Site Scripting (XSS) vulnerability in Web-Settler Testimonial Slider – Free Testimonials Slider Plugin (WordPress plugin) via parameters mpsp_posts_bg_color, mpsp_posts_description_color, mpsp_slide_nav_button_color.
Technical Analysis
The vector marks this flaw as remotely reachable over the network, with low attack complexity — no special timing or configuration is needed, and no interaction from a victim user.
CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Reaching this weakness in Testimonial Slider <= 3.5.8.3 takes an account at Editor level or above. Cross-site scripting happens when input from a request is written into a page without being escaped for the context it lands in, so the browser parses attacker-supplied text as markup or script.
Injected script runs with the privileges of whoever views the affected page, which is how these flaws turn into administrator session theft, silent account creation or persistent backdoors in page content. For Testimonial Slider the fix is 3.5.8.4: builds <= 3.5.8.3 are affected, anything from 3.5.8.4 onward is not.
Remediation
Update to version 3.5.8.4, or a newer patched version
How does WordSec protect against this?
An attacker needs Editor access first, so the firewall sees the attempt as traffic from a logged-in account: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: Testimonial Slider 3.5.8.4 closes this, and updating the plugin is the step that ends it.
- Firewall
- Alerts
External References
Related records
Other vulnerabilities in Testimonial Slider – Free Testimonials Slider Plugin
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