Cyber Resilience

CVE-2024-21495

Crypto Weakness in Greenpau Caddy-Security ≤ 1.0.42

Crypto Weakness
Published
17 February 2024
Modified
17 June 2026
Patch / advisory
View advisory
CVSS Score v3.1 6.5
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
EPSS Score 0.0068 49th percentile
Risk Priority 52 floored blend · peak EPSS

Summary

CVE-2024-21495 is a medium-severity Use of Insufficiently Random Values (CWE-330) vulnerability in Greenpau Caddy-Security. Its CVSS base score is 6.5 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Forge Web Credentials (T1606); ranked at the 49th 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 SC-12 (Cryptographic Key Establishment and Management) and SC-13 (Cryptographic Protection) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

A04:2025 Cryptographic Failures

EU & UK References

Vulnerability Data

Versions of the package github.com/greenpau/caddy-security before 1.0.42 are vulnerable to Insecure Randomness due to using an insecure random number generation library which could possibly be predicted via a brute-force search. Attackers could use the potentially predictable nonce value used for…

more

authentication purposes in the OAuth flow to conduct OAuth replay attacks. In addition, insecure randomness is used while generating multifactor authentication (MFA) secrets and creating API keys in the database package.

CWE(s)
CWE-330

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.
attack.mitre.org →
T1606.001 Web Cookies Credential Access
Adversaries may forge web cookies that can be used to gain access to web applications or Internet services.
attack.mitre.org →
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.
attack.mitre.org →
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.
attack.mitre.org →
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.
attack.mitre.org →
T1563 Remote Service Session Hijacking Lateral Movement
Adversaries may take control of preexisting sessions with remote services to move laterally in an environment.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2024-21494Same product: Greenpau Caddy-Security
CVE-2024-21497Same product: Greenpau Caddy-Security
CVE-2024-21493Same product: Greenpau Caddy-Security
CVE-2024-21499Same product: Greenpau Caddy-Security
CVE-2024-56089Shared CWE-330
CVE-2026-14570Shared CWE-330
CVE-2024-36389Shared CWE-330
CVE-2023-6376Shared CWE-330
CVE-2023-4462Shared CWE-330
CVE-2024-4185Shared CWE-330

Affected Assets

greenpau
caddy-security
≤ 1.0.42

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)

—

Mitigating Controls (NIST 800-53 r5) AI

SC-12 Cryptographic Key Establishment and Management good match

SC-12 requires proper cryptographic key establishment and management, which structurally mandates use of sufficient randomness for key generation.

SC-13 Cryptographic Protection partial match

SC-13 requires selection and implementation of approved cryptographic algorithms and methods, which inherently depend on and enforce sufficiently random values.

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

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.

A.8.24 Use of cryptography mostly match
prevents

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

A.8.29 Security testing in development and acceptance mostly match
finds

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

A.8.25 Secure development life cycle partial match
prevents

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

A.8.28 Secure coding partial match
prevents

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

A.8.5 Secure authentication partial match
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