Responsive WordPress Slider <= 2.2.0 - Authenticated (Subscriber+) Stored Cross-Site Scripting
Strategic Overview
- Status
- Unpatched
- Affected Plugin
- Responsive WordPress Slider
- Affected Version
<= 2.2.0- CVSS
- 6.4Medium
- Weakness type
- CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
- CVE
CVE-2021-24544
At a glance
CVE-2021-24544 is a medium-severity Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in the Responsive WordPress Slider WordPress plugin, affecting versions <= 2.2.0. It carries a CVSS score of 6.4 (reachable over the network; low attack complexity). Exploitation requires an authenticated account at Subscriber level or above. No fixed release has been reported yet; treat installations running this software as exposed. Disclosed September 2021, reported by Veshraj Ghimire.
Vulnerability Overview
The Responsive WordPress Slider WordPress plugin through 2.2.0 does not sanitise and escape some of the Slider options, allowing Cross-Site Scripting payloads to be set in them. Furthermore, as by default any authenticated user is allowed to create Sliders (https://wordpress.org/support/topic/slider-can-be-changed-from-any-user-even-subscriber/, such settings can be changed in the plugin's settings), this would allow user with a role as low as subscriber to perform Cross-Site Scripting attacks against logged in admins viewing the slider list and could lead to privilege escalation by creating a rogue admin account for example.
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 Responsive WordPress Slider <= 2.2.0 takes an account at Subscriber 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. No fixed build of this plugin is recorded for Responsive WordPress Slider yet, so installs running <= 2.2.0 stay exposed until the vendor ships one.
Remediation
No known patch available. Please review the vulnerability's details in depth and employ mitigations based on your organization's risk tolerance. It may be best to uninstall the affected software and find a replacement.
How does WordSec protect against this?
An attacker needs Subscriber 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. No patched version is recorded yet, which is the case where a filtering layer matters most, because there is nothing to update to.
- Firewall
- Alerts
External References
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