CVE-2021-29448Public exploitNetwork attack vector

Admin-browser script execution via crafted DNS query

Published Apr 15, 2021 · Updated Aug 3, 2024

Stored XSS in Pi-hole Web Interface 5.4 and earlier allows remote attackers to execute script in an administrator's browser via DNS queries. A crafted domain is recorded by the DNS service and rendered as active markup in the long-term Query Log when its Blacklist control is selected. The attacker needs network access to the DNS server, and an authenticated administrator must select the matching log entry, exposing that session's data and controls and allowing service shutdown.

CVSS severity7.6
High
EPSS probability0.67%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stored XSS in Pi-hole Web Interface 5.4 and earlier allows remote attackers to execute script in an administrator's browser via DNS queries. A crafted domain is recorded by the DNS service and rendered as active markup in the long-term Query Log when its Blacklist control is selected. The attacker needs network access to the DNS server, and an authenticated administrator must select the matching log entry, exposing that session's data and controls and allowing service shutdown.

The record

CVE
CVE-2021-29448
Published
Apr 15, 2021
Updated
Aug 3, 2024
Vendor
Pi-hole
Product
Pi-hole Web Interface
Classifications
CWE-79, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 15, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=<= 5.4

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Pi-hole · Pi-hole Web Interfaceversion=<= 5.4

Published CVSS scores

7.6Pi-hole GitHub Security AdvisoryCVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:H
8.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1203Exploitation for Client Execution

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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