CVE-2023-32247Network attack vector

Unauthenticated denial of service via session allocation

Published Jul 24, 2023 · Updated Aug 2, 2024

Resource exhaustion in Linux Kernel ksmbd allows remote attackers to interrupt the system through SMB2_SESSION_SETUP requests. The smb2_sess_setup path accepts repeated pre-authentication requests with SessionId 0 and creates new session objects without reclaiming expired sessions, allowing memory use to grow indefinitely. Authentication is not required, but ksmbd must be enabled and reachable; successful exploitation exhausts host memory and interrupts system operation.

CVSS severity7.5
High
EPSS probability3.87%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Resource exhaustion in Linux Kernel ksmbd allows remote attackers to interrupt the system through SMB2_SESSION_SETUP requests. The smb2_sess_setup path accepts repeated pre-authentication requests with SessionId 0 and creates new session objects without reclaiming expired sessions, allowing memory use to grow indefinitely. Authentication is not required, but ksmbd must be enabled and reachable; successful exploitation exhausts host memory and interrupts system operation.

The record

CVE
CVE-2023-32247
Published
Jul 24, 2023
Updated
Aug 2, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-401, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 24, 2023CVE publishedPublication date reported by the CVE source.
  2. Aug 2, 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 vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

7.5Red Hat, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
7.5Zero Day InitiativeCVSS:3.1/AV:N/AC:L/PR:N/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)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-401Missing Release of Memory after Effective Lifetime
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

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Your stack

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