Cyber Resilience

CVE-2023-38585

Auth Bypass in Cbc Nr4H Firmware

Published
23 August 2023
Modified
21 November 2024
Patch / advisory
CVSS Score v3.1 8.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.011 62th percentile
Risk Priority 68 floored blend · peak EPSS

CVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.

Summary

CVE-2023-38585 is a high-severity Improper Authentication (CWE-287) vulnerability in Cbc Nr4H Firmware. Its CVSS base score is 8.8 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique External Remote Services (T1133); ranked in the top 38% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

Improper authentication vulnerability in the CBC products allows a remote authenticated attacker to execute an arbitrary OS command on the device or alter its settings. As for the affected products/versions, see the detailed information provided by the vendor. Note that…

more

NR4H, NR8H, NR16H series and DR-16F, DR-8F, DR-4F, DR-16H, DR-8H, DR-4H, DR-4M41 series are no longer supported, therefore updates for those products are not provided.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1133 External Remote Services Persistence
Adversaries may leverage external-facing remote services to initially access and/or persist within a network.
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.
T1040 Network Sniffing Credential Access
Adversaries may passively sniff network traffic to capture information about an environment, including authentication material passed over the network.
T1134 Access Token Manipulation Stealth
Adversaries may modify access tokens to operate under a different user or system security context to perform actions and bypass access controls.
T1185 Browser Session Hijacking Collection
Adversaries may take advantage of security vulnerabilities and inherent functionality in browser software to change content, modify user-behaviors, and intercept information as part of various browser session hijacking techniques.
T1505.003 Web Shell Persistence
Adversaries may backdoor web servers with web shells to establish persistent access to systems.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2023-40144Same product: Cbc Dr-16F42A
CVE-2023-40158Same product: Cbc Dr-16F42A
CVE-2026-28514Shared CWE-287
CVE-2024-35184Shared CWE-287
CVE-2023-45038Shared CWE-287
CVE-2024-47174Shared CWE-287
CVE-2026-20182Shared CWE-287
CVE-2025-37107Shared CWE-287
CVE-2026-8216Shared CWE-287
CVE-2023-43551Shared CWE-287

Affected Assets

cbc
nr4h firmware
all versions
cbc
nr8h firmware
all versions
cbc
nr16h firmware
all versions
cbc
dr-16f42a firmware
all versions
cbc
dr-16f45at firmware
all versions
cbc
dr-8f42a firmware
all versions
cbc
dr-8f45at firmware
all versions
cbc
dr-4fx1 firmware
all versions
cbc
dr-16h firmware
all versions
cbc
dr-8h firmware
all versions
+13 more product configuration(s) — see NVD for full list

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)
  • 8 hardening rules · 5 OS baselines
Validate
Prove the fix (OWASP ASVS)
  • V6.4.4
  • V6.5.4
  • V6.5.5
  • V6.5.7

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-287

Detects unauthorized successful logons resulting from improper authentication implementations.

addresses: CWE-287

Documented procedures ensure personnel are trained on authentication mechanisms, tangibly lowering the risk of improper authentication being exploited.

addresses: CWE-287

Security awareness training instructs users on secure authentication practices and avoiding credential compromise.

addresses: CWE-287

Training on authentication mechanisms and best practices decreases the occurrence of improper authentication.

addresses: CWE-287

Non-repudiation requires strong authentication mechanisms to irrefutably attribute performed actions to specific individuals or processes.

addresses: CWE-287

Session content review can reveal authentication bypasses or failures in session establishment.

addresses: CWE-287

Review of authentication-related audit records can detect improper authentication mechanisms or bypasses.

addresses: CWE-287

Assessments check authentication mechanisms for correct implementation and effectiveness, reducing successful authentication bypass attempts.

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-03 mostly match
prevents

PR.AA-03 directly enforces authentication mechanisms that eliminate most improper-authentication defects, yet CWE-287 spans additional vectors (missing checks, flawed protocols, session handling) that one control does not fully close.

PR.AA-04 mostly match
prevents

PR.AA-04 directly enables verification of identity assertions (mostly preventing CWE-287 in that scope) yet leaves many other authentication failure modes unaddressed (only partial prevention overall).

PR.AA-01 partial match
prevents

PR.AA-01 supplies and governs credentials/tokens that authentication relies on, removing some weak-credential cases, yet leaves verification logic, missing checks, and protocol flaws untouched.

PR.AA-02 partial match
prevents

PR.AA-02 ensures valid enrollment and unique credential binding, which reduces some improper-auth risks at issuance time but leaves runtime claim verification untouched, so each direction only partially addresses the other.

PR.PS-01 partial match
prevents

PR.PS-01 can enforce auth-related settings via hardened baselines and default reviews, blocking some config-based instances of CWE-287, yet leaves code-level auth flaws untouched so neither direction reaches mostly.

PR.PS-02 partial match
prevents

Patching/maintenance can remediate some known auth vulnerabilities after deployment (partial forward) but does not address the design or implementation of authentication logic itself (none reverse).

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

Requiring authentication methods whose strength matches the sensitivity of the data and mandating multi-factor authentication directly blocks attempts to access resources without proving identity.

prevents

Verifying user identity before issuing replacement credentials and forcing changes after compromise reduces the likelihood that authentication bypass can be achieved through stolen or weak credentials.

prevents

Mandating segregated approval and oversight for non-human identities reduces the chance that weak or orphaned credentials can be exploited for unauthorized authentication.

mitigates

Requiring authentication mechanisms and technical parameters for secure connections ensures that network services verify user identity before granting access, preventing exploitation of missing or weak authentication.

prevents

Security requirements specified early and verified through testing drive the consistent implementation of authentication mechanisms, decreasing the likelihood that authentication steps are omitted or incorrectly applied.

prevents

Defining the required level of trust in entity identity and the authentication mechanisms to achieve it ensures that authentication is explicitly addressed rather than omitted.

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 (1 rule)
  • V-248827 OL 8 must not have the rsh-server package installed. prevents CWE-287
RHEL 7 (3 rules)
  • V-204425 The Red Hat Enterprise Linux operating system must be configured so that the SSH daemon does not allow authentication using an empty password. prevents CWE-287
  • V-204442 The Red Hat Enterprise Linux operating system must not have the rsh-server package installed. prevents CWE-287
  • V-204424 The Red Hat Enterprise Linux operating system must not allow accounts configured with blank or null passwords. prevents CWE-287
RHEL 8 (1 rule)
  • V-230492 RHEL 8 must not have the rsh-server package installed. prevents CWE-287
Ubuntu 22.04 (1 rule)
  • V-260470 Ubuntu 22.04 LTS, when booted, must require authentication upon booting into single-user and maintenance modes. prevents CWE-287
Ubuntu 24.04 (2 rules)
  • V-270675 Ubuntu 24.04 LTS when booted must require authentication upon booting into single-user and maintenance modes. prevents CWE-287
  • V-270714 Ubuntu 24.04 LTS must not allow accounts configured in Pluggable Authentication Modules (PAM) with blank or null passwords. prevents CWE-287

References