CVE-2021-43413Public exploit

Root privilege escalation via shared pager port

Published Nov 7, 2021 · Updated Aug 4, 2024

GNU Hurd before 0.9 20210404-9 allows local users to gain root by modifying readable files through memory mappings. A single pager port is reused for every process mapping the same file, so a reader's writable mapping can change the shared backing file despite lacking write permission. Local access and read permission on a privileged file are sufficient to alter protected data and escalate to full root access.

CVSS severity8.8
High
EPSS probability1.97%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

GNU Hurd before 0.9 20210404-9 allows local users to gain root by modifying readable files through memory mappings. A single pager port is reused for every process mapping the same file, so a reader's writable mapping can change the shared backing file despite lacking write permission. Local access and read permission on a privileged file are sufficient to alter protected data and escalate to full root access.

The record

CVE
CVE-2021-43413
Published
Nov 7, 2021
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
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

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

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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