CVE-2021-38343

Nested Pages <= 3.1.15 - Open Redirect

2021-08-25 00:00

Strategic Overview

Status: Patched in 3.1.16
Affected Plugin: Nested Pages
Affected Version: <= 3.1.15
CVSS: 4.7Medium
Weakness type: CWE-601 · URL Redirection to Untrusted Site ('Open Redirect')
CVE: CVE-2021-38343

At a glance

CVE-2021-38343 is a medium-severity URL Redirection to Untrusted Site ('Open Redirect') vulnerability in the Nested Pages WordPress plugin, affecting versions <= 3.1.15. It carries a CVSS score of 4.7 (reachable over the network; low attack complexity). Exploitation requires no authentication. The issue is fixed in version 3.1.16; sites on affected versions should update now. Disclosed August 2021, reported by Ram.

Vulnerability Overview

The Nested Pages WordPress plugin <= 3.1.15 was vulnerable to an Open Redirect via the `page` POST parameter in the `npBulkActions`, `npBulkEdit`, `npListingSort`, and `npCategoryFilter` `admin_post` actions.

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-601: URL Redirection to Untrusted Site ('Open Redirect')

Reaching this weakness in Nested Pages <= 3.1.15 takes a caller who can reach the endpoint. An open redirect is a page that takes a destination from the request and sends the browser there without checking that the destination belongs to the site.

A link that starts on a trusted domain finishes on an attacker's, which is what makes phishing and consent-screen abuse credible to the person clicking it. For Nested Pages the fix is 3.1.16: builds <= 3.1.15 are affected, anything from 3.1.16 onward is not.

Remediation

Update to version 3.1.16, or a newer patched version

How does WordSec protect against this?

The attempt arrives as an ordinary request to Nested Pages: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: Nested Pages 3.1.16 closes this, and updating the plugin is the step that ends it.

Firewall
Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2021-38343 https://www.wordfence.com/threat-intel/vulnerabilities/id/40a08542-5e2e-4689-b26f-99a1350185cc https://nvd.nist.gov/vuln/detail/CVE-2021-38343

Related records

Other vulnerabilities in Nested Pages

CVSS Vector

4.7

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

Base

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

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