Vulnerability in Linux kernel (CVE-2025-21716)
Summary
Vulnerability in Linux kernel (CVE-2025-21716). Risk of unauthorized operations or information disclosure.
Original description
The description as published by the source.
In the Linux kernel, the following vulnerability has been resolved:
vxlan: Fix uninit-value in vxlan_vnifilter_dump()
KMSAN reported an uninit-value access in vxlan_vnifilter_dump() [1].
If the length of the netlink message payload is less than
sizeof(struct tunnel_msg), vxlan_vnifilter_dump() accesses bytes
beyond the message. This can lead to uninit-value access. Fix this by
returning an error in such situations.
[1]
BUG: KMSAN: uninit-value in vxlan_vnifilter_dump+0x328/0x920 drivers/net/vxlan/vxlan_vnifilter.c:422
vxlan_vnifilter_dump+0x328/0x920 drivers/net/vxlan/vxlan_vnifilter.c:422
rtnl_dumpit+0xd5/0x2f0 net/core/rtnetlink.c:6786
netlink_dump+0x93e/0x15f0 net/netlink/af_netlink.c:2317
__netlink_dump_start+0x716/0xd60 net/netlink/af_netlink.c:2432
netlink_dump_start include/linux/netlink.h:340 [inline]
rtnetlink_dump_start net/core/rtnetlink.c:6815 [inline]
rtnetlink_rcv_msg+0x1256/0x14a0 net/core/rtnetlink.c:6882
netlink_rcv_skb+0x467/0x660 net/netlink/af_netlink.c:2542
rtnetlink_rcv+0x35/0x40 net/core/rtnetlink.c:6944
netlink_unicast_kernel net/netlink/af_netlink.c:1321 [inline]
netlink_unicast+0xed6/0x1290 net/netlink/af_netlink.c:1347
netlink_sendmsg+0x1092/0x1230 net/netlink/af_netlink.c:1891
sock_sendmsg_nosec net/socket.c:711 [inline]
__sock_sendmsg+0x330/0x3d0 net/socket.c:726
____sys_sendmsg+0x7f4/0xb50 net/socket.c:2583
___sys_sendmsg+0x271/0x3b0 net/socket.c:2637
__sys_sendmsg net/socket.c:2669 [inline]
__do_sys_sendmsg net/socket.c:267…
Source: GitHub Security Advisories (Global) 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-2025-21716 has been found in Linux kernel.
Risk of unauthorized operations or information disclosure. CVSS score: 5.5/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Linux kernel CVE-2025-21716" on the vendor's site.
CVE-2025-21716 (Linux kernel) — CWE-908 / CVSS v3 5.5
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 (CWE-908) exists in Linux kernel.
Check the vendor advisory for the affected versions of Linux kernel.
Severity: Medium (CVSS 5.5/10). Risk of unauthorized operations or information disclosure.
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
- BellSoft Alpaquita BELL-CVE-2025-21716 linux-lts Fixed in: 6.1.130-r0
- Debian DEBIAN-CVE-2025-21716 linux Fixed in: 6.1.129-1
- Ubuntu UBUNTU-CVE-2025-21716 linux-hwe-edge
References
- advisory nvd.nist.gov
- advisory github.com
- 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.debian.org
- web cert-portal.siemens.com
- web github.com