CVE-2023-6660Network attack vector

Kernel memory disclosure via failed NFS copyin

Published Dec 13, 2023 · Updated Feb 13, 2025

Information disclosure in FreeBSD 13.2-RELEASE through 13.2-RELEASE-p7 and 14.0-RELEASE through 14.0-RELEASE-p2 allows remote authenticated users to read kernel memory. The NFS client append path can fail to copy userspace data into an mbuf yet treat the copy as successful, causing stale packet-buffer contents to be written instead. Exploitation requires access to run a program against an NFS client mount; direct I/O is also affected only when its default-disabled sysctl is enabled for synchronous writes.

CVSS severity6.5
Medium
EPSS probability0.62%
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

Information disclosure in FreeBSD 13.2-RELEASE through 13.2-RELEASE-p7 and 14.0-RELEASE through 14.0-RELEASE-p2 allows remote authenticated users to read kernel memory. The NFS client append path can fail to copy userspace data into an mbuf yet treat the copy as successful, causing stale packet-buffer contents to be written instead. Exploitation requires access to run a program against an NFS client mount; direct I/O is also affected only when its default-disabled sysctl is enabled for synchronous writes.

The record

CVE
CVE-2023-6660
Published
Dec 13, 2023
Updated
Feb 13, 2025
Vendor
The FreeBSD Project
Product
FreeBSD
Classifications
T1005
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Dec 13, 2023CVE publishedPublication date reported by the CVE source.
  2. Feb 13, 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?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=13.2-RELEASE <p8
  2. Affected versionversion=14.0-RELEASE <p3

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

The FreeBSD Project · FreeBSDversion=13.2-RELEASE <p8; version=14.0-RELEASE <p3

Published CVSS scores

6.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1005Data from Local System

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