CVE-2021-24495

Marmoset Viewer < 1.9.3 - Reflected Cross-Site Scripting

2021-07-06 00:00
John Jackson

Strategic Overview

Status
Patched in 1.9.3
Affected Plugin
Marmoset Viewer
Affected Version
< 1.9.3
CVSS
6.1Medium
Weakness type
CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CVE
CVE-2021-24495
View all Marmoset Viewer vulnerabilities

At a glance

CVE-2021-24495 is a medium-severity Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in the Marmoset Viewer WordPress plugin, affecting versions < 1.9.3. It carries a CVSS score of 6.1 (reachable over the network; low attack complexity). Exploitation requires no authentication. The issue is fixed in version 1.9.3; sites on affected versions should update now. Disclosed July 2021, reported by John Jackson.

Vulnerability Overview

The Marmoset Viewer WordPress plugin before 1.9.3 does not property sanitize, validate or escape the 'id' parameter before outputting back in the page, leading to a reflected Cross-Site Scripting issue.

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

Reaching this weakness in Marmoset Viewer < 1.9.3 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 Marmoset Viewer the fix is 1.9.3: builds < 1.9.3 are affected, anything from 1.9.3 onward is not.

Remediation

Update to version 1.9.3, or a newer patched version

How does WordSec protect against this?

The attempt arrives as an ordinary request to Marmoset Viewer: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: Marmoset Viewer 1.9.3 closes this, and updating the plugin is the step that ends it.

  • Firewall
  • Alerts

External References

Related records

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