Smush – Lazy Load Images, Optimize & Compress Images <= 2.9.1 - Cross-Site Scripting

2018-12-10 00:00

Strategic Overview

Status: Patched in 3.0.0
Affected Plugin: Smush – Image Optimization, Compression, Lazy Load, WebP & CDN
Affected Version: <= 2.9.1
CVSS: 9.8Critical
Weakness type: CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CVE: CVE pending

View all Smush – Image Optimization, Compression, Lazy Load, WebP & CDN vulnerabilities

At a glance

This record tracks a critical-severity Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in the Smush WordPress plugin, affecting versions <= 2.9.1. It carries a CVSS score of 9.8 (reachable over the network; low attack complexity; high confidentiality, integrity, availability impact). Exploitation requires no authentication. The issue is fixed in version 3.0.0; sites on affected versions should update now. Disclosed December 2018.

Vulnerability Overview

The Smush – Lazy Load Images, Optimize & Compress Images plugin for WordPress is vulnerable to Cross-Site Scripting leading in versions up to, and including, 2.9.1 due to insufficient input sanitization and output escaping. This makes it possible for attackers to inject malicious web scripts into the application.

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, and no interaction from a victim user. A successful exploit has high impact on confidentiality, integrity, availability — full site compromise territory.

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

Reaching this weakness in Smush <= 2.9.1 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 Smush the fix is 3.0.0: builds <= 2.9.1 are affected, anything from 3.0.0 onward is not.

Remediation

Update to version 3.0.0, or a newer patched version

How does WordSec protect against this?

The attempt arrives as an ordinary request to Smush: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: Smush 3.0.0 closes this, and updating the plugin is the step that ends it.

Firewall
Alerts

External References

https://www.wordfence.com/threat-intel/vulnerabilities/id/53b5a052-6e84-4eb5-a7f4-4e32f757f4d6

Related records

Same weakness class

4.4CVE-2022-1009: Smush XSSCVE-2022-1009

Other vulnerabilities in Smush – Image Optimization, Compression, Lazy Load, WebP & CDN

CVSS Vector

9.8

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

Base

Attack VectorNetwork
Attack ComplexityLow
Privileges RequiredNone
User InteractionNone
ScopeUnchanged
ConfidentialityHigh
IntegrityHigh
AvailabilityHigh

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