CVE-2018-18373

Support Board for WordPress <= 1.2.3 - Cross-Site Scripting

2018-10-16 00:00

Strategic Overview

Status: Patched in 1.2.4
Affected Plugin: Support Board
Affected Version: < 1.2.4
CVSS: 6.4Medium
Weakness type: CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CVE: CVE-2018-18373

At a glance

CVE-2018-18373 is a medium-severity Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in the Support Board WordPress plugin, affecting versions < 1.2.4. It carries a CVSS score of 6.4 (reachable over the network; low attack complexity). The issue is fixed in version 1.2.4; sites on affected versions should update now. Disclosed October 2018, reported by Ismail Tasdelen.

Vulnerability Overview

In the Schiocco "Support Board - Chat And Help Desk" plugin 1.2.3 for WordPress, a Stored XSS vulnerability has been discovered in file upload areas in the Chat and Help Desk sections via the msg parameter in a /wp-admin/admin-ajax.php sb_ajax_add_message action.

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 Support Board < 1.2.4 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 Support Board the fix is 1.2.4: builds < 1.2.4 are affected, anything from 1.2.4 onward is not.

Remediation

Update to version 1.2.4, or a newer patched version

How does WordSec protect against this?

The attempt arrives as an ordinary request to Support Board: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: Support Board 1.2.4 closes this, and updating the plugin is the step that ends it.

Firewall
Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2018-18373 https://www.wordfence.com/threat-intel/vulnerabilities/id/46f144c9-2cd3-4320-b987-119b672e7e30 https://nvd.nist.gov/vuln/detail/CVE-2018-18373

Related records

Same weakness class

Other vulnerabilities in Support Board

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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