What’s Vulnerable › Vulnerabilities

CVE-2021-34644: Multiplayer Games <= 3.7 Reflected Cross-Site Scripting

• Severity: medium (CVSS 6.1 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.9% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2021-08-16 · updated 2026-06-17
• Weakness: CWE-79

Description

The Multiplayer Games WordPress plugin is vulnerable to Reflected Cross-Site Scripting due to the use of $_SERVER['PHP_SELF'] in the ~/multiplayergames.php file which allows attackers to inject arbitrary web scripts, in versions up to and including 3.7.

Affected products

• Multiplayer Games: through 3.7

References

• https://plugins.trac.wordpress.org/browser/multiplayer-plugin/trunk/multiplayergames.php#L662
• https://www.wordfence.com/vulnerability-advisories/#CVE-2021-34644
• https://plugins.trac.wordpress.org/browser/multiplayer-plugin/trunk/multiplayergames.php#L662
• https://www.wordfence.com/vulnerability-advisories/#CVE-2021-34644

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