CVE-2021-24988

WP RSS Aggregator <= 4.19.2 - Subscriber+ Stored Cross-Site Scripting

2021-11-29 00:00
Krzysztof Zając

Strategic Overview

Status
Patched in 4.19.3
Affected Plugin
WP RSS Aggregator – RSS Import, Feed to Post, Autoblogging, AI Content
Affected Version
< 4.19.3
CVSS
5.4Medium
Weakness type
CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CVE
CVE-2021-24988
View all WP RSS Aggregator – RSS Import, Feed to Post, Autoblogging, AI Content vulnerabilities

At a glance

CVE-2021-24988 is a medium-severity Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in the WP RSS Aggregator WordPress plugin, affecting versions < 4.19.3. It carries a CVSS score of 5.4 (reachable over the network; low attack complexity). The issue is fixed in version 4.19.3; sites on affected versions should update now. Disclosed November 2021, reported by Krzysztof Zając.

Vulnerability Overview

The WP RSS Aggregator WordPress plugin before 4.19.3 does not sanitise and escape data before outputting it in the System Info admin dashboard, which could lead to a Stored XSS issue due to the wprss_dismiss_addon_notice AJAX action missing authorisation and CSRF checks, allowing any authenticated users, such as subscriber to call it and set a malicious payload in the addon parameter.

Technical Analysis

The vector marks this flaw as remotely reachable over the network, with low attack complexity — no special timing or configuration is needed.

CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

Reaching this weakness in WP RSS Aggregator < 4.19.3 takes a caller who can reach the endpoint. 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 WP RSS Aggregator the fix is 4.19.3: builds < 4.19.3 are affected, anything from 4.19.3 onward is not.

Remediation

Update to version 4.19.3, or a newer patched version

How does WordSec protect against this?

The attempt arrives as an ordinary request to WP RSS Aggregator: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: WP RSS Aggregator 4.19.3 closes this, and updating the plugin is the step that ends it.

  • Firewall
  • Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2021-24988https://www.wordfence.com/threat-intel/vulnerabilities/id/5776ae23-3846-41bf-92dd-948230c334bfhttps://nvd.nist.gov/vuln/detail/CVE-2021-24988

Related records

Vulnerability data © Defiant, Inc., provided under the Wordfence Intelligence T&C