CVE-2021-24737

Comments - wpDiscuz <= 7.3.0 - Authenticated Stored Cross-Site Scripting

2021-09-13 00:00

Strategic Overview

Status: Patched in 7.3.2
Affected Plugin: Comments – wpDiscuz
Affected Version: <= 7.3.0
CVSS: 4.8Medium
Weakness type: CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CVE: CVE-2021-24737

View all Comments – wpDiscuz vulnerabilities

At a glance

CVE-2021-24737 is a medium-severity Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in the Comments WordPress plugin, affecting versions <= 7.3.0. It carries a CVSS score of 4.8 (reachable over the network; low attack complexity). Exploitation requires an authenticated account. The issue is fixed in version 7.3.2; sites on affected versions should update now. Disclosed September 2021, reported by Phu Tran.

Vulnerability Overview

The Comments - wpDiscuz WordPress plugin through 7.3.0 does not properly sanitize or escape the Follow and Unfollow messages before outputting them in the page, which could allow high privilege users to perform Stored Cross-Site Scripting attacks even when the unfiltered_html capability is disallowed.

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 Comments <= 7.3.0 takes any authenticated account. 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 Comments the fix is 7.3.2: builds <= 7.3.0 are affected, anything from 7.3.2 onward is not.

Remediation

Update to version 7.3.2, or a newer patched version

How does WordSec protect against this?

The attempt arrives as an ordinary request to Comments: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: Comments 7.3.2 closes this, and updating the plugin is the step that ends it.

Firewall
Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2021-24737 https://www.wordfence.com/threat-intel/vulnerabilities/id/afbf555a-1b70-4966-9b05-46e9de04e660 https://nvd.nist.gov/vuln/detail/CVE-2021-24737

Related records

Same weakness class

Other vulnerabilities in Comments – wpDiscuz

CVSS Vector

4.8

CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N

Base

Attack VectorNetwork
Attack ComplexityLow
Privileges RequiredHigh
User InteractionRequired
ScopeChanged
ConfidentialityLow
IntegrityLow
AvailabilityNone

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