CVE-2025-21703

highpriority · track · 0EPSS 0.003 · 23 %ileDEEUFRRUUS
grimoire priorityP2 · Scheduled
Exploitable?
—
no known exploitation
Likely / severe?
0.30% (23rd) EPSS
CVSS 7.8 · high
Is it mine?
53 products
Check your exposure
Who says so?
7 sources
cnnvd · enisa_euvd · fstec_bdu · cert_bund

EPSS · scored 2026-10-27

In the Linux kernel, the following vulnerability has been resolved: netem: Update sch->q.qlen before qdisc_tree_reduce_backlog() qdisc_tree_reduce_backlog() notifies parent qdisc only if child qdisc becomes empty, therefore we need to reduce the backlog of the child qdisc before calling it. Otherwise it would miss the opportunity to call cops->qlen_notify(), in the case of DRR, it resulted in UAF since DRR uses ->qlen_notify() to maintain its active list.

01

remediations

Vendor fix, mitigation, or workaround guidance, as published by each source.

No vendor fix yet; a mitigation is available.

  • MitigationSIMATIC S7-1500 TM MFP - GNU/Linux subsystemsiemens_psirt

    Limit access to the interactive shell of the additional GNU/Linux subssytem to trusted personnel only.

  • MitigationSIMATIC S7-1500 TM MFP - GNU/Linux subsystemcisa_csaf_ot

    Limit access to the interactive shell of the additional GNU/Linux subssytem to trusted personnel only.

  • WorkaroundSIMATIC S7-1500 TM MFP - BIOSsiemens_psirt

    Only build and run applications from trusted sources

  • WorkaroundSIMATIC S7-1500 TM MFP - BIOScisa_csaf_ot

    Only build and run applications from trusted sources

  • No fix availableSIMATIC S7-1500 TM MFP - BIOSsiemens_psirt

    Currently no fix is available

  • No fix availableSIMATIC S7-1500 TM MFP - GNU/Linux subsystemsiemens_psirt

    Currently no fix is available

  • No fix availableSIMATIC S7-1500 TM MFP - BIOScisa_csaf_ot

    Currently no fix is available

  • No fix availableSIMATIC S7-1500 TM MFP - GNU/Linux subsystemcisa_csaf_ot

    Currently no fix is available

02

cvss

Technical severity, 0–10. One row per scoring source.

7.8
010

base score 0–10 · higher = more severe · hover a vector to decode

v3.17.8highCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:Hsecondary · CISA US
v3.17.8highAV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:Hsecondary · FSTEC (BDU) RU
v3.17.8highCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:Hsecondary · ENISA EU
v3.17.8highCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:Hsecondaryexploitability 1.8 · impact 5.9
v3.17.8highCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:Hsecondaryexploitability 1.8 · impact 5.9
v3.17.8highCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:Hsecondary · Siemens ProductCERT DE
03

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Exploitation: none · Automatable: no · Technical Impact: totalcoordinatorcisa_ssvcUS
04

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-416USCWE-416USCWE-416USCWE-416US
05

affected products (53)

Products and version ranges known to be affected.

showing 20 of 53
06

advisories (7)

Vendor and ecosystem advisories describing this.

  • SSA-503939SSA-503939: Vulnerabilities in the BIOS of the SIMATIC S7-1500 TM MFP2025-03-11csaf · siemens_psirtDE

    Multiple vulnerabilities have been identified in the BIOS of the SIMATIC S7-1500 TM MFP. Siemens is preparing fix versions and recommends specific countermeasures for products where fixes are not, or not yet available.

  • SSA-784472SSA-784472: Vulnerabilities in the additional GNU/Linux subsystem of the SIMATIC S7-1500 TM MFP V1.1.12026-10-13csaf · siemens_psirtDE

    Multiple vulnerabilities have been identified in the additional GNU/Linux subsystem of the SIMATIC S7-1500 TM MFP V1.1.1. Siemens is preparing fixes and recommends specific mitigations for products where fixes are not or not yet available.

  • WID-SEC-W-2025-0411Linux Kernel: Mehrere SchwachstellenDeutsch2025-02-18csaf · cert_bundDE

    Ein lokaler Angreifer kann mehrere Schwachstellen in Linux Kernel ausnutzen, um Dateien zu manipulieren oder seine Rechte zu erweitern.

  • WID-SEC-W-2025-1439Dell Secure Connect Gateway: Mehrere Schwachstellen ermöglichen nicht spezifizierten AngriffDeutsch2025-06-30csaf · cert_bundDE

    Ein Angreifer kann mehrere Schwachstellen in Dell Secure Connect Gateway ausnutzen, um einen nicht näher spezifizierten Angriff durchzuführen.

  • ICSA-25-072-03Siemens SIMATIC S7-1500 TM MFP2025-03-11icsa · cisa_csaf_otUS

    Multiple vulnerabilities have been identified in the BIOS of the SIMATIC S7-1500 TM MFP. Siemens is preparing fix versions and recommends specific countermeasures for products where fixes are not, or not yet available.

  • ICSA-26-295-16Siemens SIMATIC S7-1500 TM MFP2026-10-13icsa · cisa_csaf_otUS

    Multiple vulnerabilities have been identified in the additional GNU/Linux subsystem of the SIMATIC S7-1500 TM MFP V1.1.1. Siemens is preparing fixes and recommends specific mitigations for products where fixes are not or not yet available.

  • CERTFR-2026-AVI-1298Multiples vulnérabilités dans les produits SiemensFrançais2026-10-13vendor · certfrFR
07

also known as (4)

Other names and identifiers for this entity.

08

sources

Which sources assert this record, and when.

cnnvdenisa_euvdfstec_bducert_bundcisa_csaf_otsiemens_psirtcertfrNVDCVE.orgMITRE
published 2025-02-18modified 2026-10-15
09

references (23)

External citations — patches, advisories, analysis.

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