CVE-2023-23455

System crash via ATM classifier type confusion

Published Jan 12, 2023 · Updated Mar 20, 2025

Type confusion in the ATM queuing discipline in Linux kernel 2.6.12 through 6.1.4 allows local users to crash the system. atm_tc_enqueue interprets res.class as an atm_flow_data pointer after tcf_classify returns TC_ACT_SHOT, even though that result does not supply a valid class pointer. Low-privileged local access is required; dereferencing the invalid pointer causes an out-of-bounds kernel access and a system crash.

CVSS severity5.5
Medium
EPSS probability0.27%
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

Type confusion in the ATM queuing discipline in Linux kernel 2.6.12 through 6.1.4 allows local users to crash the system. atm_tc_enqueue interprets res.class as an atm_flow_data pointer after tcf_classify returns TC_ACT_SHOT, even though that result does not supply a valid class pointer. Low-privileged local access is required; dereferencing the invalid pointer causes an out-of-bounds kernel access and a system crash.

The record

CVE
CVE-2023-23455
Published
Jan 12, 2023
Updated
Mar 20, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-843, T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jan 12, 2023CVE publishedPublication date reported by the CVE source.
  2. Mar 20, 2025Record 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?

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

5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
4.2Oracle LinuxCVSS:3.0/AV:L/AC:L/PR:H/UI:R/S:U/C:N/I:N/A:H
5.5CISA-ADPCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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 exploitUnconfirmed

Weakness, pattern, technique

CWE-843Access of Resource Using Incompatible Type ('Type Confusion')
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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