CVE-2020-8498

GistPress < 3.0.2 - Cross-Site Scripting

2020-01-31 00:00

Strategic Overview

Status: Patched in 3.0.2
Affected Plugin: gistpress
Affected Version: < 3.0.2
CVSS: 6.4Medium
Weakness type: CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CVE: CVE-2020-8498

At a glance

CVE-2020-8498 is a medium-severity Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in the gistpress WordPress plugin, affecting versions < 3.0.2. It carries a CVSS score of 6.4 (reachable over the network; low attack complexity). The issue is fixed in version 3.0.2; sites on affected versions should update now. Disclosed January 2020, reported by Paul Ritchie.

Vulnerability Overview

XSS exists in the shortcode functionality of the GistPress plugin before 3.0.2 for WordPress via the includes/class-gistpress.php id parameter. This allows an attacker with the WordPress Contributor role to execute arbitrary JavaScript code with the privileges of other users (e.g., ones who have the publish_posts capability).

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 gistpress < 3.0.2 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 gistpress the fix is 3.0.2: builds < 3.0.2 are affected, anything from 3.0.2 onward is not.

Remediation

Update to version 3.0.2, or a newer patched version

How does WordSec protect against this?

The attempt arrives as an ordinary request to gistpress: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: gistpress 3.0.2 closes this, and updating the plugin is the step that ends it.

Firewall
Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2020-8498 https://www.wordfence.com/threat-intel/vulnerabilities/id/5607882d-9112-45f9-bee0-a0c077419187 https://nvd.nist.gov/vuln/detail/CVE-2020-8498

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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