Relevanssi - A Better Search Free & Premium <= 2.16.3 & 4.14.3 - Stored Cross-Site Scripting

2021-10-19 00:00
msaari

Strategic Overview

Status
Patched in 4.14.4
Affected Plugin
Relevanssi – A Better Search
Affected Version
< 4.14.3
CVSS
7.2High
Weakness type
CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CVE
CVE pending
View all Relevanssi – A Better Search vulnerabilities

At a glance

This record tracks a high-severity Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in the Relevanssi WordPress plugin, affecting versions < 4.14.3. It carries a CVSS score of 7.2 (reachable over the network; low attack complexity). Exploitation requires no authentication. The issue is fixed in version 4.14.4; sites on affected versions should update now. Disclosed October 2021, reported by msaari.

Vulnerability Overview

The Relevanssi - A Better Search Free & Premium plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the ‘$query_link ’ parameter in versions up to, and including, 2.16.3 & 4.14.3 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

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 privileges on the target site, and no interaction from a victim user.

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

Reaching this weakness in Relevanssi < 4.14.3 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 Relevanssi the fix is 4.14.4: builds < 4.14.3 are affected, anything from 4.14.4 onward is not.

Remediation

Update to version 4.14.4, or a newer patched version

How WordSec helps

The attempt arrives as an ordinary request to Relevanssi: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: Relevanssi 4.14.4 closes this, and updating the plugin is the step that ends it.

  • Firewall
  • Alerts

External References

https://www.wordfence.com/threat-intel/vulnerabilities/id/8e12d132-c036-4665-bb8d-e31e2b155fbd

Related records

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