Jetpack <= 3.7.1 - Stored Cross-Site Scripting

2015-10-01 00:00
Marc-Alexandre Montpas

Strategic Overview

Status
Patched in 3.7.2
Affected Plugin
Jetpack – WP Security, Backup, Speed, & Growth
Affected Version
<= 3.7.1
CVSS
7.2High
Weakness type
CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CVE
CVE pending
View all Jetpack – WP Security, Backup, Speed, & Growth vulnerabilities

At a glance

This record tracks a high-severity Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in the Jetpack WordPress plugin, affecting versions <= 3.7.1. It carries a CVSS score of 7.2 (reachable over the network; low attack complexity). Exploitation requires no authentication. The issue is fixed in version 3.7.2; sites on affected versions should update now. Disclosed October 2015, reported by Marc-Alexandre Montpas.

Vulnerability Overview

Jetpack versions 3.7.0 and earlier are vulnerable to a Cross-Site Scripting vulnerability in the contact form due to improper input sanitization. This allows an unauthenticated attacker to inject JavaScript into the contact form that can potentially execute in a site administrators browser.

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.

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

Reaching this weakness in Jetpack <= 3.7.1 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 Jetpack the fix is 3.7.2: builds <= 3.7.1 are affected, anything from 3.7.2 onward is not.

Remediation

Update to version 3.7.2, or a newer patched version

How does WordSec protect against this?

The attempt arrives as an ordinary request to Jetpack: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: Jetpack 3.7.2 closes this, and updating the plugin is the step that ends it.

  • Firewall
  • Alerts

External References

https://www.wordfence.com/threat-intel/vulnerabilities/id/a1c731b9-8862-4140-b5e8-58132113e22c

Related records

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