CVE-2021-32706: (Authenticated) Remote Code Execution Possible in Web Interface 5.5

Severity: high (CVSS 8.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 60.2% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2021-08-04 · updated 2026-06-17
Weakness: CWE-94

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 `validDomainWildcard` preg_match filter allows a malicious character through that can be used to execute code, list directories, and overwrite sensitive files. The issue lies in the fact that one of the periods is not escaped, allowing any character to be used in its place. A patch for this vulnerability was released in version 5.5.1.

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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