CVE-2024-33621

Service interruption via mismatched IPvlan socket family

Published Jun 21, 2024 · Updated May 12, 2026

Improper input validation in Linux IPvlan allows local users to interrupt service by sending a raw packet through an IPv6-backed device. ipvlan_process_v4_outbound and ipvlan_process_v6_outbound pass the PF_PACKET socket from skb->sk into local IP output, where sk_mc_loop encounters the incompatible socket family and triggers WARN_ON_ONCE. Exploitation requires privileged local raw-socket access and affects availability without reported data disclosure or modification.

CVSS severity5.5
Medium
EPSS probability0.27%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper input validation in Linux IPvlan allows local users to interrupt service by sending a raw packet through an IPv6-backed device. ipvlan_process_v4_outbound and ipvlan_process_v6_outbound pass the PF_PACKET socket from skb->sk into local IP output, where sk_mc_loop encounters the incompatible socket family and triggers WARN_ON_ONCE. Exploitation requires privileged local raw-socket access and affects availability without reported data disclosure or modification.

The record

CVE
CVE-2024-33621
Published
Jun 21, 2024
Updated
May 12, 2026
Vendor
Siemens
Product
SIPLUS S7-1500 CPU 1518-4 PN/DP MFP
Classifications
CWE-1287, T1499
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Jun 21, 2024CVE publishedPublication date reported by the CVE source.
  2. May 12, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=V3.1.0 <V3.1.5

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

Siemens · SIPLUS S7-1500 CPU 1518-4 PN/DP MFPversion=V3.1.0 <V3.1.5
Siemens · SIMATIC S7-1500 TM MFP - GNU/Linux subsystemversion=0 <*
The Linux Kernel Organization · Linuxversion=2ad7bf3638411cb547f2823df08166c13ab04269 <0049a623dfbbb49888de7f0c2f33a582b5ead989; version=2ad7bf3638411cb547f2823df08166c13ab04269 <13c4543db34e0da5a7d2f550b6262d860f248381; version=2ad7bf3638411cb547f2823df08166c13ab04269 <183c4b416454b9983dc1b8aa0022b748911adc48; version=2ad7bf3638411cb547f2823df08166c13ab04269 <1abbf079da59ef559d0ab4219d2a0302f7970761; version=2ad7bf3638411cb547f2823df08166c13ab04269 <54213c09801e0bd2549ac42961093be36f65a7d0; version=2ad7bf3638411cb547f2823df08166c13ab04269 <54768bacfde60e8e4757968d79f8726711dd2cf5; version=2ad7bf3638411cb547f2823df08166c13ab04269 <b3dc6e8003b500861fa307e9a3400c52e78e4d3a; version=2ad7bf3638411cb547f2823df08166c13ab04269 <cb53706a3403ba67f4040b2a82d9cf79e11b1a48; version=3.19
Siemens · SIMATIC S7-1500 CPU 1518F-4 PN/DP MFPversion=V3.1.0 <V3.1.5
Siemens · SCALANCE XCM/XRM/XCH/XRH-300 familyversion=0 <V3.1
Siemens · RUGGEDCOM RST2428Pversion=0 <V3.1
Siemens · SIMATIC S7-1500 CPU 1518-4 PN/DP MFPversion=V3.1.0 <V3.1.5

Published CVSS scores

5.5NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
4.4Siemens ProductCERTCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-1287Improper Validation of Specified Type of Input
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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