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Vulnerabilities

Vulnerability · CVE-2023-3609

A use-after-free vulnerability in the Linux kernel's net/sched: cls_u32 component can be exploited to achieve local privilege escalation.

Published Jul 21, 2023 · catalog updated Oct 14, 2026 · linux kernel

Check if you run it

No confirmed exploitation is on record for CVE-2023-3609. EPSS is 0.49%. Act only if a listed version of linux kernel is installed.

Gaps on this record

  • No vendor fix or required action is stored. Compare the linked advisory before you change production.
Severity
High7.8
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.49%
Remediation
Advisory link
Affected products
cpe debian/debian linux · cpe linux/linux kernel

A use-after-free vulnerability in the Linux kernel's net/sched: cls_u32 component can be exploited to achieve local privilege escalation. If tcf_change_indev() fails, u32_set_parms() will immediately return an error after incrementing or decrementing the reference counter in tcf_bind_filter(). If an attacker can control the reference counter and set it to zero, they can cause the reference to be freed, leading to a use-after-free vulnerability. We recommend upgrading past commit 04c55383fa5689357bcdd2c8036725a55ed632bc.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • cpe debian/debian linux10.0
  • cpe linux/linux kernel6.4

How to fix CVE-2023-3609

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2023-3609. EPSS is 0.49%. Act only if a listed version of linux kernel is installed.

Which versions are affected?

Compare what you have installed with debian/debian linux 10.0; linux/linux kernel 6.4. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

CWE-416: Use After Free. EPSS 0.49%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. Jul 21, 2023 · NIST NVD

    Detected

    A use-after-free vulnerability in the Linux kernel's net/sched: cls_u32 component can be exploited to achieve local privilege escalation. If tcf_change_indev() fails, u32_set_parms() will immediately return an error after incrementing or decrementing the reference counter in tcf_bind_filter(). If an attacker can control the reference counter and set it to zero, they can cause the reference to be f

  2. Oct 14, 2026 · NIST NVD

    Updated

    A use-after-free vulnerability in the Linux kernel's net/sched: cls_u32 component can be exploited to achieve local privilege escalation. If tcf_change_indev() fails, u32_set_parms() will immediately return an error after incrementing or decrementing the reference counter in tcf_bind_filter(). If an attacker can control the reference counter and set it to zero, they can cause the reference to be f

Sources

  • CVE.orgVulnerability recordCVE-2023-3609

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2023-3609

    30-day exploitation probability 0.5%

    first.org
  • NIST NVDVulnerability recordCVE-2023-3609

    A use-after-free vulnerability in the Linux kernel's net/sched: cls_u32 component can be exploited to achieve local privilege escalation. If tcf_change_indev() fails, u32_set_parms() will immediately return an error after incrementing or decrementing the reference counter in t

    nvd.nist.gov
  • Packet Storm SecurityCited referencehttp://packetstormsecurity.com/files/175072/Kernel-Live-Patch-Security-Notice-LSN-0098-1.html

    Packet Storm link already published on the finding.

    packetstormsecurity.com
  • Packet Storm SecurityCited referencehttp://packetstormsecurity.com/files/175963/Kernel-Live-Patch-Security-Notice-LSN-0099-1.html

    Packet Storm link already published on the finding.

    packetstormsecurity.com

References

Freshness

Last verified in this catalog Oct 16, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.