Cyber Resilience

CVE-2023-20016

Crypto Weakness in Cisco Ucs Central Software ≤ 4.2\(3c\)

Published
23 February 2023
Modified
21 November 2024
Patch / advisory
CVSS Score v3.1 6.3
Click a component to see what it means
Raw vectorCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:H/I:N/A:N
EPSS Score 0.0011 1th percentile
Risk Priority 46 floored blend · peak EPSS

Summary

CVE-2023-20016 is a medium-severity Use of Hard-coded Cryptographic Key (CWE-321) vulnerability in Cisco Ucs Central Software. Its CVSS base score is 6.3 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Private Keys (T1552.004); ranked at the 1th 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 backup configuration feature of Cisco UCS Manager Software and in the configuration export feature of Cisco FXOS Software could allow an unauthenticated attacker with access to a backup file to decrypt sensitive information stored in the…

more

full state and configuration backup files. This vulnerability is due to a weakness in the encryption method used for the backup function. An attacker could exploit this vulnerability by leveraging a static key used for the backup configuration feature. A successful exploit could allow the attacker to decrypt sensitive information that is stored in full state and configuration backup files, such as local user credentials, authentication server passwords, Simple Network Management Protocol (SNMP) community names, and other credentials.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1552.004 Private Keys Credential Access
Adversaries may search for private key certificate files on compromised systems for insecurely stored credentials.
T1552 Unsecured Credentials Credential Access
Adversaries may search compromised systems to find and obtain insecurely stored credentials.
T1552.001 Credentials In Files Credential Access
Adversaries may search local file systems and remote file shares for files containing insecurely stored credentials.
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.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2023-20015Same product: Cisco Firepower 4100
CVE-2026-20101Same vendor: Cisco
CVE-2023-20185Same vendor: Cisco
CVE-2024-20331Same vendor: Cisco
CVE-2024-20323Same vendor: Cisco
CVE-2024-20350Same vendor: Cisco
CVE-2024-20280Same product: Cisco Ucs Central Software
CVE-2023-20234Same product: Cisco Firepower 4100
CVE-2023-20038Same vendor: Cisco
CVE-2024-1631Shared CWE-321, CWE-330

Affected Assets

cisco
ucs central software
≤ 4.2\(3c\) · ≤ 4.2\(3c\) · ≤ 4.2\(3c\)
cisco
ucs 6536 firmware
all versions
cisco
ucs 64108 firmware
all versions
cisco
ucs 6454 firmware
all versions
cisco
ucs 6200 firmware
all versions
cisco
ucs 6248up firmware
all versions
cisco
ucs 6296up firmware
all versions
cisco
ucs 6300 firmware
all versions
cisco
ucs 6324 firmware
all versions
cisco
ucs 6332 firmware
all versions
+2 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 · 4 OS baselines
Validate
Prove the fix (OWASP ASVS)

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-321 CWE-330

Proper key establishment and management processes directly preclude embedding static cryptographic keys in source code or binaries.

addresses: CWE-321

Supply chain protection includes scrutiny of cryptographic implementations, reducing hard-coded keys planted by untrusted vendors.

addresses: CWE-321

Functional and assurance requirements specified in acquisition can prohibit hard-coded cryptographic keys in delivered products.

addresses: CWE-321

Approved PKI issuance and trust stores replace ad-hoc or hard-coded keys with properly managed, signed certificates.

addresses: CWE-321

Assessments can uncover and prevent suppliers from shipping components that contain hard-coded cryptographic keys.

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.PS-06 mostly match
prevents

Secure-SDLC activities such as code review and secret scanning directly prevent embedding static keys.

PR.DS-01 partial match
prevents

Data-at-rest protection policies require proper key management and therefore discourage hard-coded keys.

PR.DS-02 partial match
prevents

Data-in-transit protection similarly depends on non-hard-coded keys for encryption.

PR.PS-01 partial match
prevents

Configuration baselines and reviews can prohibit hard-coded keys in deployed artifacts.

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 (1 rule)
  • V-271511 OL 9 must enable the hardware random number generator entropy gatherer service. prevents CWE-330
RHEL 8 (3 rules)
  • 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
  • V-230285 RHEL 8 must enable the hardware random number generator entropy gatherer service. prevents CWE-330
RHEL 9 (1 rule)
  • V-257782 RHEL 9 must enable the hardware random number generator entropy gatherer service. prevents CWE-330

References