CVE-2018-10101

WordPress Core < 4.9.5 - Security Misconfiguration with URL Hostnames

2018-04-03 00:00

Strategic Overview

Status: Patched in 3.7.26
Affected Core: WordPress 4.9
Affected Version: 3.7 – 4.9.4 · 14 branches
CVSS: 4.3Medium
Weakness type: CWE-601 · URL Redirection to Untrusted Site ('Open Redirect')
CVE: CVE-2018-10101

At a glance

CVE-2018-10101 is a medium-severity URL Redirection to Untrusted Site ('Open Redirect') vulnerability in the WordPress 4.9 WordPress release line, affecting 3.7 – 4.9.4 · 14 branches. It carries a CVSS score of 4.3 (reachable over the network; low attack complexity). The issue is fixed in version 3.7.26; sites on affected versions should update now. Disclosed April 2018.

Vulnerability Overview

Before WordPress 4.9.5, the URL validator assumed URLs with the hostname localhost were on the same host as the WordPress server.

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

Reaching this weakness in WordPress 4.9 3.7 – 4.9.4 · 14 branches 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 WordPress 4.9 the fix is 3.7.26: builds 3.7 – 4.9.4 · 14 branches are affected, anything from 3.7.26 onward is not.

Remediation

Update to one of the following versions, or a newer patched version: 3.7.26, 3.8.26, 3.9.24, 4.0.23, 4.1.23, 4.2.20, 4.3.16, 4.4.15, 4.5.14, 4.6.11, 4.7.10, 4.8.6, 4.9.5

How does WordSec protect against this?

The attempt arrives as an ordinary request to WordPress 4.9: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: updating to 3.7.26 is the step that ends it.

Firewall
Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2018-10101 https://www.wordfence.com/threat-intel/vulnerabilities/id/70352973-5fa7-40b0-9e07-eab2e96520b7 https://nvd.nist.gov/vuln/detail/CVE-2018-10101

Related records

Same weakness class

Other vulnerabilities in WordPress 4.9

CVSS Vector

4.3

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

Base

Attack VectorNetwork
Attack ComplexityLow
Privileges RequiredLow
User InteractionNone
ScopeUnchanged
ConfidentialityLow
IntegrityNone
AvailabilityNone

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