Security Resilience

CVE-2023-32247

Linux Kernel 5.15 – 5.15.145

Published
24 July 2023
Modified
21 November 2024
Patch / advisory
CVSS Score v3.1 7.5
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS Score 0.039 90th percentile
Risk Priority 66 floored blend · peak EPSS

CVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.

Summary

CVE-2023-32247 is a high-severity Missing Release of Memory after Effective Lifetime (CWE-401) vulnerability in Linux Linux Kernel. Its CVSS base score is 7.5 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Junk Data (T1001.001); ranked in the top 10% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

The vulnerability is a resource consumption flaw, tracked as CWE-401, in the Linux kernel's ksmbd component that implements an in-kernel SMB server. It occurs during handling of SMB2_SESSION_SETUP commands and allows uncontrolled allocation that can exhaust system resources, producing a denial-of-service condition. The affected software is the Linux kernel containing the ksmbd module; the issue carries a CVSS 3.1 score of 7.5.

An unauthenticated network attacker can send a series of specially crafted SMB2_SESSION_SETUP requests to trigger the flaw. Because the attack requires no credentials or user interaction and can be launched remotely, successful exploitation results in a high-impact availability loss on the target system while leaving confidentiality and integrity unaffected.

The EPSS score for this CVE started low after the July 2023 disclosure, rose materially to a peak of 0.0914 on 2025-01-22, and has since fallen to 0.0009, indicating a period of increased exploitation interest well after public release. Red Hat, NetApp, and Zero Day Initiative have published advisories referencing the issue for tracking and mitigation.

EU & UK References

Vulnerability Data

A flaw was found in the Linux kernel's ksmbd, a high-performance in-kernel SMB server. The specific flaw exists within the handling of SMB2_SESSION_SETUP commands. The issue results from the lack of control of resource consumption. An attacker can leverage this…

more

vulnerability to create a denial-of-service condition on the system.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1001.001 Junk Data Command And Control
Adversaries may add junk data to protocols used for command and control to make detection more difficult.
T1001.002 Steganography Command And Control
Adversaries may use steganographic techniques to hide command and control traffic to make detection efforts more difficult.
T1001.003 Protocol or Service Impersonation Command And Control
Adversaries may impersonate legitimate protocols or web service traffic to disguise command and control activity and thwart analysis efforts.
T1003 OS Credential Dumping Credential Access
Adversaries may attempt to dump credentials to obtain account login and credential material, normally in the form of a hash or a clear text password.
T1003.001 LSASS Memory Credential Access
Adversaries may attempt to access credential material stored in the process memory of the Local Security Authority Subsystem Service (LSASS).
T1003.004 LSA Secrets Credential Access
Adversaries with SYSTEM access to a host may attempt to access Local Security Authority (LSA) secrets, which can contain a variety of different credential materials, such as credentials for service accounts.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2023-35829Same product: Linux Linux Kernel
CVE-2023-38427Same product: Linux Linux Kernel
CVE-2023-32258Same product: Linux Linux Kernel
CVE-2023-35826Same product: Linux Linux Kernel
CVE-2023-1838Same product: Linux Linux Kernel
CVE-2023-3390Same product: Linux Linux Kernel
CVE-2023-38431Same product: Linux Linux Kernel
CVE-2023-38430Same product: Linux Linux Kernel
CVE-2023-32254Same product: Linux Linux Kernel
CVE-2023-35828Same product: Linux Linux Kernel

Affected Assets

linux
linux kernel
5.15 — 5.15.145 · 5.16 — 6.1.29 · 6.2 — 6.2.16
netapp
h300s
all versions
netapp
h410s
all versions
netapp
h500s
all versions
netapp
h700s
all versions

Mitigating Controls

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 partial match
blocks

Secure SDLC practices directly enforce proper memory allocation/deallocation via coding standards, reviews, and tooling.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

removes
removes
removes
removes
removes

References