Cyber Resilience

CVE-2026-22909

Access Control in Sick Tdc-X401Gl Firmware

Published
15 January 2026
Modified
23 January 2026
Patch / advisory
CVSS Score v3.1 7.5
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS Score 0.0051 41th percentile
Risk Priority 58 floored blend · peak EPSS

Summary

CVE-2026-22909 is a high-severity Improper Access Control (CWE-284) vulnerability in Sick Tdc-X401Gl Firmware. Its CVSS base score is 7.5 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 41th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to AC-24 (Access Control Decisions) and AC-25 (Reference Monitor) — see the control section below for these in your framework.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

CVE-2026-22909 is an improper access control vulnerability (CWE-284, CWE-863) affecting certain SICK products, where system functions can be accessed without proper authorization. This allows attackers to start, stop, or delete installed applications, potentially disrupting system operations. The vulnerability has a CVSS v3.1 base score of 7.5 (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H), indicating high severity due to its network accessibility, low attack complexity, and significant availability impact with no requirements for privileges or user interaction.

Remote attackers require no authentication or privileges to exploit this vulnerability over the network. Successful exploitation enables denial-of-service effects by manipulating installed applications, such as stopping critical processes or deleting software components, which can halt system functionality and disrupt operations in affected environments.

SICK has published detailed advisories via its PSIRT page and specific CSAF documents, including sca-2026-0001 in JSON and PDF formats, outlining mitigation steps. Additional guidance appears in CISA's ICS recommended practices, with CVSS details available via the FIRST calculator.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

Certain system functions may be accessed without proper authorization, allowing attackers to start, stop, or delete installed applications, potentially disrupting system operations.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
T1548 Abuse Elevation Control Mechanism Privilege Escalation
Adversaries may circumvent mechanisms designed to control privilege elevation to gain higher-level permissions.
T1021 Remote Services Lateral Movement
Adversaries may use [Valid Accounts](https://attack.
T1021.001 Remote Desktop Protocol Lateral Movement
Adversaries may use [Valid Accounts](https://attack.
T1021.002 SMB/Windows Admin Shares Lateral Movement
Adversaries may use [Valid Accounts](https://attack.
T1021.003 Distributed Component Object Model Lateral Movement
Adversaries may use [Valid Accounts](https://attack.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2023-23445Same vendor: Sick
CVE-2023-23446Same vendor: Sick
CVE-2023-5288Same vendor: Sick
CVE-2023-3271Same vendor: Sick
CVE-2023-3273Same vendor: Sick
CVE-2023-43696Same vendor: Sick
CVE-2026-40304Shared CWE-284, CWE-863
CVE-2025-9973Shared CWE-284, CWE-863
CVE-2023-43119Shared CWE-284, CWE-863
CVE-2023-0319Shared CWE-284, CWE-863

Affected Assets

sick
tdc-x401gl firmware
all versions

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)
  • 13 hardening rules · 4 OS baselines
Validate
Prove the fix (OWASP ASVS)
  • V10.3.5

Mitigating Controls (NIST 800-53 r5) AI

Directly enforces approved authorizations for logical access, stopping unauthorized actors from reaching resources.

AC-24 ensures access-control decisions are made and applied consistently, reducing the chance of an incorrect authorization result.

A reference monitor that is always invoked and tamper-proof forces every authorization decision through a verified, correct path.

Enforces flow-control policies that restrict information movement between subjects and objects.

Documents duties and assigns access so that no single account can bypass intended restrictions.

Limits each account to the minimum privileges needed, reducing the chance of unauthorized access.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.AA-05 mostly match
prevents

PR.AA-05 directly enforces policy-based access management and least privilege, eliminating most improper-access-control defects, yet CWE-284 also covers implementation flaws and design gaps outside a single management control.

PR.PS-01 mostly match
prevents

Hardened baselines and deviation monitoring directly eliminate most configuration-induced access-control defects, yet CWE-284 also encompasses code-level and design flaws outside the scope of configuration management alone.

PR.PS-06 mostly match
prevents

Secure SDLC practices catch most access-control defects during design/coding/testing (mostly), yet leave residual risk from runtime configuration, architecture, and operational controls (partial).

PR.AA-01 partial match
prevents

PR.AA-01 supplies managed identities/credentials that support but do not implement access-control decisions, so it only partially prevents CWE-284 in either direction.

PR.AA-03 partial match
prevents

Authentication directly blocks unauthenticated actors (partial prevention of CWE-284) but leaves authorization logic, policy enforcement, and role checks untouched, so the control neither eliminates nor fully mitigates the broader weakness.

PR.DS-01 partial match
prevents

PR.DS-01 encryption mitigates impact of failed access checks on stored data but neither implements nor constrains access-control logic itself.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

prevents

Defining and enforcing explicit access rights and restrictions for each entity directly stops the assignment of permissions that exceed what is required, eliminating the root condition that allows improper access control.

prevents

Formal authorization, role-based provisioning, and timely revocation of access rights directly stop the creation of accounts or permissions that exceed what the business actually needs.

prevents

By enforcing explicit rules on which identities or groups may perform read, write, delete or execute operations and by denying anonymous access to sensitive data, the control directly stops the creation of overly permissive or missing access-control checks.

prevents

Requiring one-to-one mapping of identities to entities and timely removal of unused identities directly stops attackers from leveraging stale or shared accounts to bypass access restrictions.

prevents

By explicitly transferring security roles and responsibilities when personnel change jobs or leave, the control reduces the chance that former employees retain access rights they no longer need, thereby limiting improper access control.

prevents

Physical entry controls enforce explicit authorization and authentication at every access point, directly stopping unauthorized actors from reaching information-processing assets.

Hardening callouts derived

Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).

Oracle Linux 8 (4 rules)
  • V-248581 OL 8 must require users to provide a password for privilege escalation. prevents CWE-863
  • V-248597 There must be no "shosts.equiv" files on the OL 8 operating system. prevents CWE-284
  • V-248598 There must be no ".shosts" files on the OL 8 operating system. prevents CWE-284
Oracle Linux 9 (2 rules)
  • V-271758 OL 9 file systems must not contain .shosts files. prevents CWE-284
  • V-271757 OL 9 file systems must not contain shosts.equiv files. prevents CWE-284
RHEL 7 (3 rules)
  • V-204430 The Red Hat Enterprise Linux operating system must be configured so that users must re-authenticate for privilege escalation. prevents CWE-863
  • V-204606 The Red Hat Enterprise Linux operating system must not contain .shosts files. prevents CWE-284
  • V-204607 The Red Hat Enterprise Linux operating system must not contain shosts.equiv files. prevents CWE-284
RHEL 8 (3 rules)
  • V-230283 There must be no shosts.equiv files on the RHEL 8 operating system. prevents CWE-284
  • V-230284 There must be no .shosts files on the RHEL 8 operating system. prevents CWE-284
  • V-251712 The RHEL 8 operating system must not be configured to bypass password requirements for privilege escalation. prevents CWE-863

References