CVE-2021-24482

Related Posts for WordPress <= 2.0.4 - Stored Cross-Site Scripting

2021-05-17 00:00

Strategic Overview

Status: Patched in 2.0.5
Affected Plugin: Related Posts for WordPress
Affected Version: <= 2.0.4
CVSS: 5.5Medium
Weakness type: CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CVE: CVE-2021-24482

At a glance

CVE-2021-24482 is a medium-severity Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in the Related Posts for WordPress WordPress plugin, affecting versions <= 2.0.4. It carries a CVSS score of 5.5 (reachable over the network; low attack complexity). The issue is fixed in version 2.0.5; sites on affected versions should update now. Disclosed May 2021, reported by R3N0.

Vulnerability Overview

The Related Posts for WordPress plugin through 2.0.4 does not sanitise its heading_text and CSS settings, allowing high privilege users (admin) to set XSS payloads in them, leading to Stored Cross-Site Scripting issues.

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 Related Posts for WordPress <= 2.0.4 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 Related Posts for WordPress the fix is 2.0.5: builds <= 2.0.4 are affected, anything from 2.0.5 onward is not.

Remediation

Update to version 2.0.5, or a newer patched version

How does WordSec protect against this?

The attempt arrives as an ordinary request to Related Posts for WordPress: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: Related Posts for WordPress 2.0.5 closes this, and updating the plugin is the step that ends it.

Firewall
Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2021-24482 https://www.wordfence.com/threat-intel/vulnerabilities/id/f63bf296-b34c-4f89-90eb-bba2a0461d57 https://nvd.nist.gov/vuln/detail/CVE-2021-24482

Related records

Same weakness class

CVSS Vector

5.5

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

Base

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

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