CVE-2018-17583

WP Fastest Cache <= 0.8.8.5 - Cross-Site Scripting via the rules[0][content] parameter in a wpfc_save_exclude_pages action

2018-10-09 00:00
Mohammed Ansari

Strategic Overview

Status
Patched in 0.8.8.6
Affected Plugin
WP Fastest Cache – WordPress Cache Plugin
Affected Version
<= 0.8.8.5
CVSS
6.1Medium
Weakness type
CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CVE
CVE-2018-17583
View all WP Fastest Cache – WordPress Cache Plugin vulnerabilities

At a glance

CVE-2018-17583 is a medium-severity Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in the WP Fastest Cache WordPress plugin, affecting versions <= 0.8.8.5. 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 0.8.8.6; sites on affected versions should update now. Disclosed October 2018, reported by Mohammed Ansari.

Vulnerability Overview

The WP Fastest Cache plugin 0.8.8.5 for WordPress has XSS via the rules[0][content] parameter in a wpfc_save_exclude_pages 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 privileges on the target site.

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

Reaching this weakness in WP Fastest Cache <= 0.8.8.5 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 WP Fastest Cache the fix is 0.8.8.6: builds <= 0.8.8.5 are affected, anything from 0.8.8.6 onward is not.

Remediation

Update to version 0.8.8.6, or a newer patched version

How does WordSec protect against this?

The attempt arrives as an ordinary request to WP Fastest Cache: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: WP Fastest Cache 0.8.8.6 closes this, and updating the plugin is the step that ends it.

  • Firewall
  • Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2018-17583https://www.wordfence.com/threat-intel/vulnerabilities/id/ef6538e7-8cde-4c49-9965-0624a25ffe65https://nvd.nist.gov/vuln/detail/CVE-2018-17583

Related records

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