Related Posts for WordPress < 1.8.2 - Reflected Cross-Site Scripting

2015-04-20 00:00

Strategic Overview

Status: Patched in 1.8.2
Affected Plugin: Related Posts for WordPress
Affected Version: < 1.8.2
CVSS: 6.1Medium
Weakness type: CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CVE: CVE pending

At a glance

This record tracks 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 < 1.8.2. 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 1.8.2; sites on affected versions should update now. Disclosed April 2015.

Vulnerability Overview

The Related Posts for WordPress plugin for WordPress is vulnerable to Cross-Site Scripting in versions up to, not including, 1.8.2 due to insufficient input sanitization and output escaping. The same vulnerability exists in Related Posts Premium up to, not including, 1.3.4. This makes it possible for attackers to inject arbitrary web scripts that execute in a victim's browser.

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 Related Posts for WordPress < 1.8.2 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 1.8.2: builds < 1.8.2 are affected, anything from 1.8.2 onward is not.

Remediation

Update to version 1.8.2, 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 1.8.2 closes this, and updating the plugin is the step that ends it.

Firewall
Alerts

External References

https://www.wordfence.com/threat-intel/vulnerabilities/id/4f32d1fe-17ea-48c0-b276-36c8fcaad4a6

Related records

Same weakness class

CVSS Vector

6.1

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

Base

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

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