CVE-2021-36841

YITH Maintenance Mode <= 1.3.7 - Stored Cross-Site Scripting

2021-09-15 11:59

Strategic Overview

Status: Patched in 1.3.8
Affected Plugin: YITH Maintenance Mode
Affected Version: <= 1.3.7
CVSS: 6.9Medium
Weakness type: CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CVE: CVE-2021-36841

View all YITH Maintenance Mode vulnerabilities

At a glance

CVE-2021-36841 is a medium-severity Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in the YITH Maintenance Mode WordPress plugin, affecting versions <= 1.3.7. It carries a CVSS score of 6.9 (reachable over the network; low attack complexity; high confidentiality impact). The issue is fixed in version 1.3.8; sites on affected versions should update now. Disclosed September 2021, reported by Asif Nawaz Minhas.

Vulnerability Overview

Authenticated Stored Cross-Site Scripting (XSS) vulnerability in YITH Maintenance Mode (WordPress plugin) versions <= 1.3.7, vulnerable parameter &yith_maintenance_newsletter_submit_label. Possible even when unfiltered HTML is disallowed by WordPress configuration.

Technical Analysis

The vector marks this flaw as remotely reachable over the network, with low attack complexity — no special timing or configuration is needed. A successful exploit has high impact on confidentiality.

CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

Reaching this weakness in YITH Maintenance Mode <= 1.3.7 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 YITH Maintenance Mode the fix is 1.3.8: builds <= 1.3.7 are affected, anything from 1.3.8 onward is not.

Remediation

Update to version 1.3.8, or a newer patched version

How does WordSec protect against this?

The attempt arrives as an ordinary request to YITH Maintenance Mode: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: YITH Maintenance Mode 1.3.8 closes this, and updating the plugin is the step that ends it.

Firewall
Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2021-36841 https://www.wordfence.com/threat-intel/vulnerabilities/id/8f617090-f2cf-4ac4-8d09-c1d5c21e120d https://nvd.nist.gov/vuln/detail/CVE-2021-36841

Related records

Same weakness class

CVSS Vector

6.9

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

Base

Attack VectorNetwork
Attack ComplexityLow
Privileges RequiredHigh
User InteractionRequired
ScopeChanged
ConfidentialityHigh
IntegrityLow
AvailabilityNone

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