VulnerabilityPublished 21 Jun 2024Updated 28 Oct 2026

CVE-2024-33621: Linux kernel · ipvlan: Dont Use skb->sk in ipvlan_process_v{4,6}_outbound

Affects Linux kernelSource GCVE Database

Not known to be exploited · CVSS 5.5 Medium · fixed in 5.4.0-1130.140~18.04.1 : update Linux kernel when convenient.

Data as of 28 Oct 2026, 10:59 UTC

CVSS 3.1 base score

5.5Medium

How severe the flaw is on the 0–10 CVSS scale.

Patch: Available – fixed in 5.4.0-1130.140~18.04.1, 5.4.0-1135.142~18.04.1, 5.4.0-1134.143~18.04.1 +71

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Attack Vector: Local
Attack Complexity: Low
Privileges Required: Low
User Interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: None
Availability: High

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Local: The vulnerable component is not bound to the network stack and the attacker’s path is via read/write/execute capabilities. Either: the attacker exploits the vulnerability by accessing the target system locally (e.g., keyboard, console), or remotely (e.g., SSH); or the attacker relies on User Interaction by another person to perform actions required to exploit the vulnerability (e.g., tricking a legitimate user into opening a malicious document).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: Low: The attacker is authorized with (i.e., requires) privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges may have the ability to cause an impact only to non-sensitive resources.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: High: There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 21 Jun 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.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade to a fixed release listed under Affected software.

Patches and advisories

Affected software

Product	Affected	Fixed in
Ubuntu 24.04 LTSlinux`pkg:deb/ubuntu/linux?arch=source&distro=noble`Other threats	Affected <6.8.0-44.44	Fixed in 6.8.0-44.44
Ubuntu 24.04 LTSlinux-aws`pkg:deb/ubuntu/linux-aws?arch=source&distro=noble`Other threats	Affected <6.8.0-1015.16	Fixed in 6.8.0-1015.16
Ubuntu 24.04 LTSlinux-azure`pkg:deb/ubuntu/linux-azure?arch=source&distro=noble`Other threats	Affected <6.8.0-1014.16	Fixed in 6.8.0-1014.16
Ubuntu 24.04 LTSlinux-gcp`pkg:deb/ubuntu/linux-gcp?arch=source&distro=noble`Other threats	Affected <6.8.0-1014.16	Fixed in 6.8.0-1014.16
Ubuntu 24.04 LTSlinux-gke`pkg:deb/ubuntu/linux-gke?arch=source&distro=noble`Other threats	Affected <6.8.0-1010.13	Fixed in 6.8.0-1010.13
Ubuntu 24.04 LTSlinux-ibm`pkg:deb/ubuntu/linux-ibm?arch=source&distro=noble`Other threats	Affected <6.8.0-1012.12	Fixed in 6.8.0-1012.12

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: ipvlan: Dont Use skb->sk in ipvlan_process_v{4,6}_outbound Raw packet from PF_PACKET socket ontop of an IPv6-backed ipvlan device will hit WARN_ON_ONCE() in sk_mc_loop() through sch_direct_xmit() path. WARNING: CPU: 2 PID: 0 at net/core/sock.c:775 sk_mc_loop+0x2d/0x70 Modules linked in: sch_netem ipvlan rfkill cirrus drm_shmem_helper sg drm_kms_helper CPU: 2 PID: 0 Comm: swapper/2 Kdump: loaded Not tainted 6.9.0+ #279 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 RIP: 0010:sk_mc_loop+0x2d/0x70 Code: fa 0f 1f 44 00 00 65 0f b7 15 f7 96 a3 4f 31 c0 66 85 d2 75 26 48 85 ff 74 1c RSP: 0018:ffffa9584015cd78 EFLAGS: 00010212 RAX: 0000000000000011 RBX: ffff91e585793e00 RCX: 0000000002c6a001 RDX: 0000000000000000 RSI: 0000000000000040 RDI: ffff91e589c0f000 RBP: ffff91e5855bd100 R08: 0000000000000000 R09: 3d00545216f43d00 R10: ffff91e584fdcc50 R11: 00000060dd8616f4 R12: ffff91e58132d000 R13: ffff91e584fdcc68 R14: ffff91e5869ce800 R15: ffff91e589c0f000 FS: 0000000000000000(0000) GS:ffff91e898100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f788f7c44c0 CR3: 0000000008e1a000 CR4: 00000000000006f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <IRQ> ? __warn (kernel/panic.c:693) ? sk_mc_loop (net/core/sock.c:760) ? report_bug (lib/bug.c:201 lib/bug.c:219) ? handle_bug (arch/x86/kernel/traps.c:239) ? exc_invalid_op (arch/x86/kernel/traps.c:260 (discriminator 1)) ? asm_exc_invalid_op (./arch/x86/include/asm/idtentry.h:621) ? sk_mc_loop (net/core/sock.c:760) ip6_finish_output2 (net/ipv6/ip6_output.c:83 (discriminator 1)) ? nf_hook_slow (net/netfilter/core.c:626) ip6_finish_output (net/ipv6/ip6_output.c:222) ? __pfx_ip6_finish_output (net/ipv6/ip6_output.c:215) ipvlan_xmit_mode_l3 (drivers/net/ipvlan/ipvlan_core.c:602) ipvlan ipvlan_start_xmit (drivers/net/ipvlan/ipvlan_main.c:226) ipvlan dev_hard_start_xmit (net/core/dev.c:3594) sch_direct_xmit (net/sched/sch_generic.c:343) __qdisc_run (net/sched/sch_generic.c:416) net_tx_action (net/core/dev.c:5286) handle_softirqs (kernel/softirq.c:555) __irq_exit_rcu (kernel/softirq.c:589) sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1043) The warning triggers as this: packet_sendmsg packet_snd //skb->sk is packet sk __dev_queue_xmit __dev_xmit_skb //q->enqueue is not NULL __qdisc_run sch_direct_xmit dev_hard_start_xmit ipvlan_start_xmit ipvlan_xmit_mode_l3 //l3 mode ipvlan_process_outbound //vepa flag ipvlan_process_v6_outbound ip6_local_out __ip6_finish_output ip6_finish_output2 //multicast packet sk_mc_loop //sk->sk_family is AF_PACKET Call ip{6}_local_out() with NULL sk in ipvlan as other tunnels to fix this.

GCVE source: db.gcve.eu
OSV ID: UBUNTU-CVE-2024-33621
Osv Schema Version: 1.7.0
Ecosystems: Ubuntu:Pro:14.04:LTS, Ubuntu:Pro:16.04:LTS, Ubuntu:16.04:LTS, Ubuntu:Pro:FIPS-updates:16.04:LTS, Ubuntu:Pro:FIPS:16.04:LTS, Ubuntu:Pro:18.04:LTS, Ubuntu:18.04:LTS, Ubuntu:Pro:FIPS-updates:18.04:LTS, Ubuntu:Pro:FIPS:18.04:LTS, Ubuntu:20.04:LTS, Ubuntu:Pro:FIPS-updates:20.04:LTS, Ubuntu:Pro:FIPS:20.04:LTS, Ubuntu:22.04:LTS, Ubuntu:Nvidia-BlueField:22.04:LTS, Ubuntu:Pro:Realtime:22.04:LTS, Ubuntu:Pro:FIPS-preview:22.04:LTS, Ubuntu:Pro:FIPS-updates:22.04:LTS, Ubuntu:24.04:LTS, Ubuntu:Pro:Realtime:24.04:LTS, Ubuntu:Pro:FIPS-updates:24.04:LTS
CVSS version: 3.1

References

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