Use-After-Free in Linux kernel (CVE-2024-26996)
Summary
Vulnerability in Linux kernel (CVE-2024-26996). Successful exploitation can lead to full system takeover.
Original description
The description as published by the source.
In the Linux kernel, the following vulnerability has been resolved:
usb: gadget: f_ncm: Fix UAF ncm object at re-bind after usb ep transport error
When ncm function is working and then stop usb0 interface for link down,
eth_stop() is called. At this piont, accidentally if usb transport error
should happen in usb_ep_enable(), 'in_ep' and/or 'out_ep' may not be enabled.
After that, ncm_disable() is called to disable for ncm unbind
but gether_disconnect() is never called since 'in_ep' is not enabled.
As the result, ncm object is released in ncm unbind
but 'dev->port_usb' associated to 'ncm->port' is not NULL.
And when ncm bind again to recover netdev, ncm object is reallocated
but usb0 interface is already associated to previous released ncm object.
Therefore, once usb0 interface is up and eth_start_xmit() is called,
released ncm object is dereferrenced and it might cause use-after-free memory.
[function unlink via configfs]
usb0: eth_stop dev->port_usb=ffffff9b179c3200
--> error happens in usb_ep_enable().
NCM: ncm_disable: ncm=ffffff9b179c3200
--> no gether_disconnect() since ncm->port.in_ep->enabled is false.
NCM: ncm_unbind: ncm unbind ncm=ffffff9b179c3200
NCM: ncm_free: ncm free ncm=ffffff9b179c3200 <-- released ncm
[function link via configfs]
NCM: ncm_alloc: ncm alloc ncm=ffffff9ac4f8a000
NCM: ncm_bind: ncm bind ncm=ffffff9ac4f8a000
NCM: ncm_set_alt: ncm=ffffff9ac4f8a000 alt=0
usb0: eth_open dev->port_usb=ffffff9b179c3200 <-- previous releas…
Source: NIST National Vulnerability Database NVD
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-2024-26996 has been found in Linux kernel.
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 CVE-2024-26996" on the vendor's site.
CVE-2024-26996 (Linux kernel) — 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.
Check the vendor advisory for the affected versions of Linux kernel.
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
-
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 を使っているサービスとバージョンを洗い出す。
-
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。
Affected packages
Fix status by distribution
Fixed packages published by each distribution for this CVE
- Debian DEBIAN-CVE-2024-26996 linux
- Ubuntu UBUNTU-CVE-2024-26996 linux
References
- advisory github.com
- advisory nvd.nist.gov
- package git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web lists.fedoraproject.org
- web lists.fedoraproject.org
- web lists.fedoraproject.org