CVE-2021-36864

Quiz And Survey Master <= 7.3.4 - Reflected Cross-Site Scripting

2022-10-21 00:00
Ngo Van Thien

Strategic Overview

Status
Patched in 7.3.5
Affected Plugin
Quiz and Survey Master (QSM) – Quiz Maker & Survey Maker
Affected Version
<= 7.3.4
CVSS
6.1Medium
Weakness type
CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CVE
CVE-2021-36864
View all Quiz and Survey Master (QSM) – Quiz Maker & Survey Maker vulnerabilities

At a glance

CVE-2021-36864 is a medium-severity Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in the Quiz and Survey Master (QSM) WordPress plugin, affecting versions <= 7.3.4. It carries a CVSS score of 6.1 (reachable over the network; low attack complexity). Exploitation requires no authentication. The issue is fixed in version 7.3.5; sites on affected versions should update now. Disclosed October 2022, reported by Ngo Van Thien.

Vulnerability Overview

The Quiz And Survey Master plugin for WordPress is vulnerable to Reflected Cross-Site Scripting via several parameters in versions up to, and including, 7.3.4 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that execute if they can successfully trick a user into performing an action such as clicking on a link.

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.

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

Reaching this weakness in Quiz and Survey Master (QSM) <= 7.3.4 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 Quiz and Survey Master (QSM) the fix is 7.3.5: builds <= 7.3.4 are affected, anything from 7.3.5 onward is not.

Remediation

Update to version 7.3.5, or a newer patched version

How does WordSec protect against this?

The attempt arrives as an ordinary request to Quiz and Survey Master (QSM): WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: Quiz and Survey Master (QSM) 7.3.5 closes this, and updating the plugin is the step that ends it.

  • Firewall
  • Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2021-36864https://www.wordfence.com/threat-intel/vulnerabilities/id/5113b58b-7d2e-40cd-8669-a5597321106fhttps://nvd.nist.gov/vuln/detail/CVE-2021-36864

Related records

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