CVE-2021-43411Public exploit

Root privilege escalation via stale process port

Published Nov 7, 2021 · Updated Aug 4, 2024

A setuid exec race in GNU Hurd before 0.9 20210404-9 allows local users to gain full root access through an old process port. The exec path separately reauthenticates the process, assigns its replacement task, and invalidates the old process port, exposing a privileged transition window. A local account that can run a setuid executable and retain the old process port can control the newly privileged process.

CVSS severity7.5
High
EPSS probability1.27%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

A setuid exec race in GNU Hurd before 0.9 20210404-9 allows local users to gain full root access through an old process port. The exec path separately reauthenticates the process, assigns its replacement task, and invalidates the old process port, exposing a privileged transition window. A local account that can run a setuid executable and retain the old process port can control the newly privileged process.

The record

CVE
CVE-2021-43411
Published
Nov 7, 2021
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-362, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Nov 7, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 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?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

7.5NIST NVDCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
8.5NIST NVDAV:N/AC:M/Au:S/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.

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No observations available

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

Weakness, pattern, technique

CWE-362Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
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

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Your stack

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