CVE-2024-50038: Linux kernel · netfilter: xtables: avoid NFPROTO_UNSPEC where needed
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 5.5 Medium · fixed in 5.15.0-1073.79~20.04.1 : update Linux kernel when convenient.
Data as of 28 Oct 2026, 11:13 UTC
- Patch
- Available – fixed in 5.15.0-1073.79~20.04.1, 5.15.0-1078.87~20.04.1, 5.15.0-1072.80~20.04.1 +58
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 21 Oct 2024
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Patches and advisories
- ubuntu.com/security/notices/USN-7166-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7166-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7166-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7186-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7186-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7194-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7166-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-7276-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7277-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7310-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7383-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7384-1 (opens in a new tab)
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 24.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-azure-6.11pkg:deb/ubuntu/linux-azure-6.11?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-azure-nvidiapkg:deb/ubuntu/linux-azure-nvidia?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
Description
In the Linux kernel, the following vulnerability has been resolved: netfilter: xtables: avoid NFPROTO_UNSPEC where needed syzbot managed to call xt_cluster match via ebtables: WARNING: CPU: 0 PID: 11 at net/netfilter/xt_cluster.c:72 xt_cluster_mt+0x196/0x780 [..] ebt_do_table+0x174b/0x2a40 Module registers to NFPROTO_UNSPEC, but it assumes ipv4/ipv6 packet processing. As this is only useful to restrict locally terminating TCP/UDP traffic, register this for ipv4 and ipv6 family only. Pablo points out that this is a general issue, direct users of the set/getsockopt interface can call into targets/matches that were only intended for use with ip(6)tables. Check all UNSPEC matches and targets for similar issues: - matches and targets are fine except if they assume skb_network_header() is valid -- this is only true when called from inet layer: ip(6) stack pulls the ip/ipv6 header into linear data area. - targets that return XT_CONTINUE or other xtables verdicts must be restricted too, they are incompatbile with the ebtables traverser, e.g. EBT_CONTINUE is a completely different value than XT_CONTINUE. Most matches/targets are changed to register for NFPROTO_IPV4/IPV6, as they are provided for use by ip(6)tables. The MARK target is also used by arptables, so register for NFPROTO_ARP too. While at it, bail out if connbytes fails to enable the corresponding conntrack family. This change passes the selftests in iptables.git.
References
- ubuntu.com/security/CVE-2024-50038 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2024-50038 (opens in a new tab)
- git.kernel.org/linus/0bfcb7b71e735560077a42847f69597ec7dcc326 (opens in a new tab)
- git.kernel.org/stable/c/85ff9a0f793ca52c527e75cd40a69c948627ebde (opens in a new tab)
- git.kernel.org/stable/c/8f482bb7e27b37f1f734bb9a8eeb28b23d59d189 (opens in a new tab)
- git.kernel.org/stable/c/997f67d813ce0cf5eb3cdb8f124da68141e91b6c (opens in a new tab)
- git.kernel.org/stable/c/4cdc55ec6222bb195995cc58f7cb46e4d8907056 (opens in a new tab)
- git.kernel.org/stable/c/0bfcb7b71e735560077a42847f69597ec7dcc326 (opens in a new tab)
- ubuntu.com/security/notices/USN-7166-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7166-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7166-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7186-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7186-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7194-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7166-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-7276-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7277-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7310-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7383-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7384-1 (opens in a new tab)