CVE-2021-20780

Currency Switcher <= 1.1.6 - Cross-site request forgery

2021-07-06 00:00
Mizuki Takagi

Strategic Overview

Status
Patched in 1.1.7
Affected Plugin
WPCS – WordPress Currency Switcher Professional
Affected Version
<= 1.1.6
CVSS
8.8High
Weakness type
CWE-352 · Cross-Site Request Forgery (CSRF)
CVE
CVE-2021-20780
View all WPCS – WordPress Currency Switcher Professional vulnerabilities

At a glance

CVE-2021-20780 is a high-severity Cross-Site Request Forgery (CSRF) vulnerability in the WPCS WordPress plugin, affecting versions <= 1.1.6. It carries a CVSS score of 8.8 (reachable over the network; low attack complexity; high confidentiality, integrity, availability impact). Exploitation requires no authentication. The issue is fixed in version 1.1.7; sites on affected versions should update now. Disclosed July 2021, reported by Mizuki Takagi.

Vulnerability Overview

The Currency Switcher plugin for WordPress is vulnerable to Cross-Site Request Forgery in versions up to, and including, 1.1.6. This is due to missing or incorrect nonce validation on the print_plugin_options() function. This makes it possible for unauthenticated attackers to update the plugin's settings and inject malicious web scripts granted they can trick a site administrator into performing an action such as clicking on a link.

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. A successful exploit has high impact on confidentiality, integrity, availability — full site compromise territory.

CWE-352: Cross-Site Request Forgery (CSRF)

WPCS <= 1.1.6 carries this weakness at print_plugin_options(), and reaching it takes a caller who can reach the endpoint. Cross-site request forgery abuses the fact that browsers attach a victim's cookies to any request, so a state-changing action that only checks who you are, not whether you meant to act, can be triggered from another site.

An attacker who gets a logged-in user to load a crafted page can perform that action as them, with the impact scaling to whatever the victim's role is allowed to do. For WPCS the fix is 1.1.7: builds <= 1.1.6 are affected, anything from 1.1.7 onward is not.

Remediation

Update to version 1.1.7, or a newer patched version

How does WordSec protect against this?

The attempt arrives as an ordinary request to WPCS: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: WPCS 1.1.7 closes this, and updating the plugin is the step that ends it.

  • Firewall
  • Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2021-20780https://www.wordfence.com/threat-intel/vulnerabilities/id/4a56a838-5dfa-477a-92b2-fdac3d1ab2afhttps://nvd.nist.gov/vuln/detail/CVE-2021-20780

Related records

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