CVE-2021-24357

FooGallery <= 2.0.34 - Stored Cross-Site Scripting

2021-05-31 00:00

Strategic Overview

Status: Patched in 2.0.35
Affected Plugin: Gallery : FooGallery
Affected Version: < 2.0.35
CVSS: 6.4Medium
Weakness type: CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CVE: CVE-2021-24357

View all Gallery : FooGallery vulnerabilities

At a glance

CVE-2021-24357 is a medium-severity Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in the Gallery WordPress plugin, affecting versions < 2.0.35. It carries a CVSS score of 6.4 (reachable over the network; low attack complexity). The issue is fixed in version 2.0.35; sites on affected versions should update now. Disclosed May 2021, reported by avolume.

Vulnerability Overview

In the Best Image Gallery & Responsive Photo Gallery – FooGallery WordPress plugin before 2.0.35, the Custom CSS field of each gallery is not properly sanitised or validated before being being output in the page where the gallery is embed, leading to a stored 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 interaction from a victim user.

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

Reaching this weakness in Gallery < 2.0.35 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 Gallery the fix is 2.0.35: builds < 2.0.35 are affected, anything from 2.0.35 onward is not.

Remediation

Update to version 2.0.35, or a newer patched version

How does WordSec protect against this?

The attempt arrives as an ordinary request to Gallery: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: Gallery 2.0.35 closes this, and updating the plugin is the step that ends it.

Firewall
Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2021-24357 https://www.wordfence.com/threat-intel/vulnerabilities/id/13c22ad6-eecb-4f05-9dce-76a721b4744c https://nvd.nist.gov/vuln/detail/CVE-2021-24357

Related records

Same weakness class

Other vulnerabilities in Gallery : FooGallery

CVSS Vector

6.4

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

Base

Attack VectorNetwork
Attack ComplexityLow
Privileges RequiredLow
User InteractionNone
ScopeChanged
ConfidentialityLow
IntegrityLow
AvailabilityNone

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