CVE-2021-29005Public exploitNetwork attack vector

Root privilege escalation via passwordless sudo chmod

Published Oct 11, 2021 · Updated Jul 9, 2026

Privilege escalation in rConfig Server 3.9.6 allows local users with Apache-account access to obtain root privileges through sudo chmod. The installed sudoers policy lets the Apache account run chmod as root without a password, allowing permissions on root-owned files to be changed. Exploitation requires control of the low-privileged Apache account; the published proof of concept makes /etc/passwd writable and appends a root account.

CVSS severity8.8
High
EPSS probability2.15%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Privilege escalation in rConfig Server 3.9.6 allows local users with Apache-account access to obtain root privileges through sudo chmod. The installed sudoers policy lets the Apache account run chmod as root without a password, allowing permissions on root-owned files to be changed. Exploitation requires control of the low-privileged Apache account; the published proof of concept makes /etc/passwd writable and appends a root account.

The record

CVE
CVE-2021-29005
Published
Oct 11, 2021
Updated
Jul 9, 2026
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-276, T1548.003
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Oct 11, 2021CVE publishedPublication date reported by the CVE source.
  2. Jul 9, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

9.0NIST NVDAV:N/AC:L/Au:S/C:C/I:C/A:C
8.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/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.

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No observations available

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

Weakness, pattern, technique

CWE-276Incorrect Default Permissions
T1548.003Sudo and Sudo Caching

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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