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Public proof of conceptFix available

CVE-2021-32706

A public proof of concept exists; no exploitation attested.

  • Published2021-08-04
  • Fixed in5.5.1
  • WeaknessCWE-94

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

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.

Timeline

dates in UTC
  1. 2021-08-0418:15CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-11-03 21:37 UTC
Indicators tagged with this CVE, per day0 indicators over 7 days
Block these indicators
  • Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2021-32706?format=txt
  • CSV export: https://api.ismalicious.com/edl/cve/CVE-2021-32706?format=csv
  • TAXII collection of exploited CVEs
  • The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD
Pi-hole
BranchAffectedFixed in
5.5< 5.5.15.5.1

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Fix

  1. Update Pi-hole to 5.5.1

Advisories and patches

Detection

Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof-of-concept repositories
none listed
PoC-in-GitHub
Metasploit modules
1 moduleauxiliary/admin/http/pihole_domains_api_execrank: normalModule metadata: Metasploit Framework, © Rapid7, Inc., BSD-3-Clause.
Metasploit Framework

Sources

  • CNACVSS 3.17.6known since 2026-10-23
  • NVDCVSS 3.18.8read 2026-10-23
  • NVDCVSS 2.06.5read 2026-10-23
  • CNAweakness (CWE)CWE-94known since 2026-10-23
  • FIRST EPSSEPSS score60.2 %read 2026-11-03
  • Metasploit FrameworkMetasploit modules1known since 2026-11-01

Identifiers

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Published
2021-08-04
Last Modified
2026-06-17
NVD status
Modified

Frequently asked questions

What is CVE-2021-32706?

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.

Is CVE-2021-32706 actively exploited?

Active exploitation of CVE-2021-32706 has not been confirmed. Its EPSS score was 60.2% on 2026-11-03, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2021-32706?

CVE-2021-32706 has a CVSS v3 base score of 8.8 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

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Sources for this record