CVE-2018-20156

WP Maintenance Mode <= 2.0.6 - Remote Code Execution

2018-12-14 00:00

Strategic Overview

Status: Patched in 2.0.7
Affected Plugin: LightStart – Maintenance Mode, Coming Soon and Landing Page Builder
Affected Version: < 2.0.7
CVSS: 9.1Critical
Weakness type: CWE-20 · Improper Input Validation
CVE: CVE-2018-20156

View all LightStart – Maintenance Mode, Coming Soon and Landing Page Builder vulnerabilities

At a glance

CVE-2018-20156 is a critical-severity Improper Input Validation vulnerability in the LightStart WordPress plugin, affecting versions < 2.0.7. It carries a CVSS score of 9.1 (reachable over the network; low attack complexity; high confidentiality, integrity, availability impact). The issue is fixed in version 2.0.7; sites on affected versions should update now. Disclosed December 2018, reported by Sean Murphy.

Vulnerability Overview

The WP Maintenance Mode plugin before 2.0.7 for WordPress allows remote authenticated "site administrator" users to execute arbitrary PHP code throughout a multisite network.

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. A successful exploit has high impact on confidentiality, integrity, availability — full site compromise territory.

CWE-20: Improper Input Validation

Reaching this weakness in LightStart < 2.0.7 takes a caller who can reach the endpoint. Improper input validation means the application accepts input without confirming it has the form, type or range the code downstream assumes.

The concrete impact depends on where the unvalidated value lands, which is why records in this class range from cosmetic bugs to full compromise. For LightStart the fix is 2.0.7: builds < 2.0.7 are affected, anything from 2.0.7 onward is not.

Remediation

Update to version 2.0.7, or a newer patched version

How does WordSec protect against this?

The attempt arrives as an ordinary request to LightStart: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: LightStart 2.0.7 closes this, and updating the plugin is the step that ends it.

Firewall
Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2018-20156 https://www.wordfence.com/threat-intel/vulnerabilities/id/2cf2201d-6da0-4f66-9135-c6b34ef7c65f https://nvd.nist.gov/vuln/detail/CVE-2018-20156

Related records

Other vulnerabilities in LightStart – Maintenance Mode, Coming Soon and Landing Page Builder

CVSS Vector

9.1

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

Base

Attack VectorNetwork
Attack ComplexityLow
Privileges RequiredHigh
User InteractionNone
ScopeChanged
ConfidentialityHigh
IntegrityHigh
AvailabilityHigh

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