CVE-2023-24626Public exploit

Local process interruption via unchecked SIGHUP target

Published Apr 8, 2023 · Updated May 9, 2025

Improper signal authorization in GNU Screen 4.9.0 and earlier allows local users to interrupt arbitrary processes via SIGHUP. The MSG_QUERY handler in socket.c accepts an attacker-controlled apid field and sends SIGHUP without adequately checking the target process user identifier. Reachability requires a setuid or setgid installation and local access; the signal can terminate or otherwise disrupt the chosen process.

CVSS severity6.5
Medium
EPSS probability0.54%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper signal authorization in GNU Screen 4.9.0 and earlier allows local users to interrupt arbitrary processes via SIGHUP. The MSG_QUERY handler in socket.c accepts an attacker-controlled apid field and sends SIGHUP without adequately checking the target process user identifier. Reachability requires a setuid or setgid installation and local access; the signal can terminate or otherwise disrupt the chosen process.

The record

CVE
CVE-2023-24626
Published
Apr 8, 2023
Updated
May 9, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-732, T1489
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 8, 2023CVE publishedPublication date reported by the CVE source.
  2. May 9, 2025Record 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

6.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H
6.5CISA-ADPCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H
7.8GitHub Advisory DatabaseCVSS:3.1/AV:L/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)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-732Incorrect Permission Assignment for Critical Resource
T1489Service Stop

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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