Use-After-Free in Linux kernel's net/sched (CVE-2023-3609)
Summary
Vulnerability in Linux kernel's net/sched (CVE-2023-3609). Successful exploitation can lead to full system takeover.
Original description
The description as published by the source.
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.
Source: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2023-3609 has been found in Linux kernel's net/sched.
Successful exploitation can lead to full system takeover. CVSS score: 7.8/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Linux kernel's net/sched CVE-2023-3609" on the vendor's site.
CVE-2023-3609 (Linux kernel's net/sched) — CWE-416 / CVSS v3 7.8
Attack vector: local / no user interaction
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
Use-after-free (CWE-416) exists in Linux kernel's net/sched.
Check the vendor advisory for the affected versions of Linux kernel's net/sched.
Severity: High (CVSS 7.8/10). Successful exploitation can lead to full system takeover.
Update to the patched release per vendor advisory.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Audit SBOM/dependencies to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
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1Identify exposure identify
Audit SBOM/dependencies for affected components.資産台帳・SBOM・依存マニフェストで Linux kernel's net/sched を使っているサービスとバージョンを洗い出す。
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2Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Fix status by distribution
Fixed packages published by each distribution for this CVE
- Debian DEBIAN-CVE-2023-3609 linux Fixed in: 5.10.191-1
- Ubuntu UBUNTU-CVE-2023-3609 linux-hwe-edge
References
- advisory packetstormsecurity.com
- advisory packetstormsecurity.com
- advisory lists.debian.org
- advisory security.netapp.com
- advisory debian.org
- advisory github.com
- patch git.kernel.org
- patch kernel.dance
- patch lists.debian.org
- web git.kernel.org
- web nvd.nist.gov
- web security.netapp.com
- web cert-portal.siemens.com
- web cert-portal.siemens.com
- web github.com