CVE-2021-32793: Stored XSS Vulnerability in the Pi-hole Webinterface

Severity: medium (CVSS 4.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.8% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2021-08-04 · updated 2026-06-17
Weakness: CWE-79

Description

Pi-hole's Web interface provides a central location to manage a Pi-hole instance and review performance statistics. Prior to Pi-hole Web interface version 5.5.1, the function to add domains to blocklists or allowlists is vulnerable to a stored cross-site-scripting vulnerability. User input added as a wildcard domain to a blocklist or allowlist is unfiltered in the web interface. Since the payload is stored permanently as a wildcard domain, this is a persistent XSS vulnerability. A remote attacker can therefore attack administrative user accounts through client-side attacks. Pi-hole Web Interface version 5.5.1 contains a patch for this vulnerability.

Affected products

pi-hole: before 5.5.1 — fixed in 5.5.1

How to fix

Upgrade to a fixed version: pi-hole 5.5.1. Check the vendor advisory for mitigations.

References

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