Cyber Resilience

CVE-2023-20185

Crypto Weakness in Cisco Nx-Os 14.0\(1h\) … 16.0\(2h\)

Published
12 July 2023
Modified
21 November 2024
Patch / advisory
CVSS Score v3.1 7.4
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
EPSS Score 0.0035 27th percentile
Risk Priority 55 floored blend · peak EPSS

Summary

CVE-2023-20185 is a high-severity Use of Insufficiently Random Values (CWE-330) vulnerability in Cisco Nx-Os. Its CVSS base score is 7.4 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Forge Web Credentials (T1606); ranked at the 27th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

A vulnerability in the Cisco ACI Multi-Site CloudSec encryption feature of Cisco Nexus 9000 Series Fabric Switches in ACI mode could allow an unauthenticated, remote attacker to read or modify intersite encrypted traffic. This vulnerability is due to an issue…

more

with the implementation of the ciphers that are used by the CloudSec encryption feature on affected switches. An attacker with an on-path position between the ACI sites could exploit this vulnerability by intercepting intersite encrypted traffic and using cryptanalytic techniques to break the encryption. A successful exploit could allow the attacker to read or modify the traffic that is transmitted between the sites. Cisco has not released and will not release software updates that address this vulnerability.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1606 Forge Web Credentials Credential Access
Adversaries may forge credential materials that can be used to gain access to web applications or Internet services.
T1606.001 Web Cookies Credential Access
Adversaries may forge web cookies that can be used to gain access to web applications or Internet services.
T1110 Brute Force Credential Access
Adversaries may use brute force techniques to gain access to accounts when passwords are unknown or when password hashes are obtained.
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.
T1557 Adversary-in-the-Middle Credential Access
Adversaries may attempt to position themselves between two or more networked devices using an adversary-in-the-middle (AiTM) technique to support follow-on behaviors such as [Network Sniffing](https://attack.
T1558 Steal or Forge Kerberos Tickets Credential Access
Adversaries may attempt to subvert Kerberos authentication by stealing or forging Kerberos tickets to enable [Pass the Ticket](https://attack.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-20101Same vendor: Cisco
CVE-2024-20321Same product: Cisco Nx-Os
CVE-2024-20267Same product: Cisco Nx-Os
CVE-2024-20331Same vendor: Cisco
CVE-2023-20016Same vendor: Cisco
CVE-2024-20301Same vendor: Cisco
CVE-2026-20129Same vendor: Cisco
CVE-2023-20214Same vendor: Cisco
CVE-2023-20238Same vendor: Cisco
CVE-2026-20182Same vendor: Cisco

Affected Assets

cisco
nx-os
14.0\(1h\), 14.0\(2c\), 14.0\(3c\), 14.0\(3d\), 14.1\(1i\)

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)
  • 22 hardening rules · 7 OS baselines
Validate
Prove the fix (OWASP ASVS)
  • V11.4.2
  • V14.1.2
  • V14.2.4

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-326 CWE-330

Establishment procedures require selection and generation of keys with adequate length and strength for the chosen algorithm.

addresses: CWE-326

Maintaining currency with technologies and practices reduces selection of encryption mechanisms that provide inadequate strength.

addresses: CWE-326

Updated assessments identify when previously adequate encryption strength no longer meets current attack capabilities or compliance drivers.

addresses: CWE-326

Specifies required cryptography types and parameters, preventing selection of inadequate encryption strength.

addresses: CWE-326

Prompt patching corrects inadequate encryption strength when vendors release updates that increase key sizes or algorithm security.

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.DS-01 mostly match
prevents

Strong encryption is required to protect confidentiality of data-at-rest.

PR.DS-02 mostly match
prevents

Strong encryption is required to protect confidentiality of data-in-transit.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly enforce use of cryptographically strong RNGs and catch insufficient randomness during design, coding, and testing.

PR.PS-01 partial match
prevents

Hardened baselines can enforce minimum cryptographic algorithm and key-length settings.

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

Cryptographic controls require use of approved, sufficiently random values for keys and nonces.

finds

Security testing can detect weak randomness but does not prescribe the control itself.

prevents

Secure SDLC processes include verification steps that can catch insufficient randomness but do not directly specify RNG requirements.

prevents

Secure coding standards explicitly prohibit use of weak or predictable random number generators.

degrades

Secure authentication mechanisms depend on unpredictable values (nonces, salts, session tokens) to resist guessing.

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 (3 rules)
  • V-248563 The OL 8 SSH server must be configured to use strong entropy. prevents CWE-330
  • V-248599 OL 8 must enable the hardware random number generator entropy gatherer service. prevents CWE-330
  • V-248600 OL 8 must have the packages required to use the hardware random number generator entropy gatherer service. prevents CWE-330
Oracle Linux 9 (2 rules)
  • V-271511 OL 9 must enable the hardware random number generator entropy gatherer service. prevents CWE-330
  • V-271756 OL 9 local disk partitions must implement cryptographic mechanisms to prevent unauthorized disclosure or modification of all information that requires at rest protection. prevents CWE-326
RHEL 8 (4 rules)
  • V-230224 All RHEL 8 local disk partitions must implement cryptographic mechanisms to prevent unauthorized disclosure or modification of all information that requires at rest protection. prevents CWE-326
  • V-244527 RHEL 8 must have the packages required to use the hardware random number generator entropy gatherer service. prevents CWE-330
  • V-230253 RHEL 8 must ensure the SSH server uses strong entropy. prevents CWE-330
RHEL 9 (2 rules)
  • V-257782 RHEL 9 must enable the hardware random number generator entropy gatherer service. prevents CWE-330
  • V-257879 RHEL 9 local disk partitions must implement cryptographic mechanisms to prevent unauthorized disclosure or modification of all information that requires at rest protection. prevents CWE-326
Windows Server 2016 (1 rule)
  • V-224843 Systems requiring data at rest protections must employ cryptographic mechanisms to prevent unauthorized disclosure and modification of the information at rest. prevents CWE-326

References