CVE-2021-29449Public exploit

Root privilege escalation via injected sed expressions

Published Apr 14, 2021 · Updated Apr 6, 2026

OS command injection in Pi-hole Core 5.2.4 and earlier allows local users to execute commands as root through removal actions. RemoveCustomCNAMERecord, RemoveCustomDNSAddress, and RemoveDHCPStaticAddress embed unvalidated arguments in root-run sed expressions. Exploitation requires a low-privilege shell permitted to run the Pi-hole CLI with sudo and, for each path, a populated corresponding configuration file.

CVSS severity6.3
Medium
EPSS probability1.85%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

OS command injection in Pi-hole Core 5.2.4 and earlier allows local users to execute commands as root through removal actions. RemoveCustomCNAMERecord, RemoveCustomDNSAddress, and RemoveDHCPStaticAddress embed unvalidated arguments in root-run sed expressions. Exploitation requires a low-privilege shell permitted to run the Pi-hole CLI with sudo and, for each path, a populated corresponding configuration file.

The record

CVE
CVE-2021-29449
Published
Apr 14, 2021
Updated
Apr 6, 2026
Vendor
Pi-hole
Product
Pi-hole
Classifications
CWE-78, CWE-269, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 14, 2021CVE publishedPublication date reported by the CVE source.
  2. Apr 6, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=<= 5.2.4

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Pi-hole · Pi-holeversion=<= 5.2.4

Published CVSS scores

6.3GitHub, Inc.CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:L
7.8NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
7.2NIST NVDAV:L/AC:L/Au:N/C:C/I:C/A:C

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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-78Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
CWE-269Improper Privilege Management
T1068Exploitation for Privilege Escalation

Public exploit references

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

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo