Vulnerability in Linux kernel
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-2025-21677 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-2025-21677" on the vendor's site.
CVE-2025-21677 (Linux kernel) — 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.
A vulnerability (unclassified) 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
-
1
Identify exposureidentify
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。
-
2
Post-deployment verificationverify
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
| Ecosystem | Package | Affected | Fixed |
|---|---|---|---|
| Linux | Kernel |
≥ 6.10.0, < 6.12.11 |
6.12.11 |
Fix status by distribution
Fixed packages published by each distribution for this CVE
- BellSoft Alpaquita BELL-CVE-2025-21677 linux-lts Fixed in: 6.12.41-r0
- Debian DEBIAN-CVE-2025-21677 linux Fixed in: 6.12.11-1
- Ubuntu UBUNTU-CVE-2025-21677 linux-hwe-edge
Original description The description as published by the source.
In the Linux kernel, the following vulnerability has been resolved:
pfcp: Destroy device along with udp socket's netns dismantle.
pfcp_newlink() links the device to a list in dev_net(dev) instead
of net, where a udp tunnel socket is created.
Even when net is removed, the device stays alive on dev_net(dev).
Then, removing net triggers the splat below. [0]
In this example, pfcp0 is created in ns2, but the udp socket is
created in ns1.
ip netns add ns1
ip netns add ns2
ip -n ns1 link add netns ns2 name pfcp0 type pfcp
ip netns del ns1
Let's link the device to the socket's netns instead.
Now, pfcp_net_exit() needs another netdev iteration to remove
all pfcp devices in the netns.
pfcp_dev_list is not used under RCU, so the list API is converted
to the non-RCU variant.
pfcp_net_exit() can be converted to .exit_batch_rtnl() in net-next.
[0]:
ref_tracker: net notrefcnt@00000000128b34dc has 1/1 users at
sk_alloc (./include/net/net_namespace.h:345 net/core/sock.c:2236)
inet_create (net/ipv4/af_inet.c:326 net/ipv4/af_inet.c:252)
__sock_create (net/socket.c:1558)
udp_sock_create4 (net/ipv4/udp_tunnel_core.c:18)
pfcp_create_sock (drivers/net/pfcp.c:168)
pfcp_newlink (drivers/net/pfcp.c:182 drivers/net/pfcp.c:197)
rtnl_newlink (net/core/rtnetlink.c:3786 net/core/rtnetlink.c:3897 net/core/rtnetlink.c:4012)
rtnetlink_rcv_msg (net/core/rtnetlink.c:6922)
netlink_rcv_skb (net/netlink/af_netlink.c:2542)
netlink_unicast (net/netl…
Source: NIST National Vulnerability Database NVD
References
- advisory github.com
- advisory nvd.nist.gov
- package git.kernel.org
- web git.kernel.org
- web git.kernel.org