Cyber Resilience

CVE-2024-23656

Crypto Weakness in Linuxfoundation Dex 2.37.0

Public PoCCrypto Weakness
Published
25 January 2024
Modified
17 June 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:H/I:N/A:N
EPSS Score 0.0043 36th percentile
Risk Priority 57 floored blend · peak EPSS

Summary

CVE-2024-23656 is a high-severity Inadequate Encryption Strength (CWE-326) vulnerability in Linuxfoundation Dex. Its CVSS base score is 7.5 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Downgrade Attack (T1689); ranked at the 36th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

The strongest mitigations our analysis identified map to SC-13 (Cryptographic Protection) and SC-12 (Cryptographic Key Establishment and Management) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

Dex is an identity service that uses OpenID Connect to drive authentication for other apps. Dex 2.37.0 serves HTTPS with insecure TLS 1.0 and TLS 1.1. `cmd/dex/serve.go` line 425 seemingly sets TLS 1.2 as minimum version, but the whole `tlsConfig`…

more

is ignored after `TLS cert reloader` was introduced in v2.37.0. Configured cipher suites are not respected either. This issue is fixed in Dex 2.38.0.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1689 Downgrade Attack Defense Impairment
Adversaries may downgrade or use a version of system features that may be outdated, vulnerable, and/or does not support updated security controls.
T1600 Weaken Encryption Defense Impairment
Adversaries may compromise a network device’s encryption capability in order to bypass encryption that would otherwise protect data communications.
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.
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.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

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CVE-2026-27133Same vendor: Linuxfoundation
CVE-2026-58253Same vendor: Linuxfoundation
CVE-2025-59353Same vendor: Linuxfoundation
CVE-2023-37918Same vendor: Linuxfoundation
CVE-2026-33215Same vendor: Linuxfoundation

Affected Assets

linuxfoundation
dex
2.37.0

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)
  • 21 hardening rules · 9 OS baselines
Validate
Prove the fix (OWASP ASVS)
  • V12.1.1
  • V12.2.1
  • V12.3.3
  • V17.2.2

Mitigating Controls (NIST 800-53 r5) AI

SC-13 requires selection and implementation of specific cryptographic algorithms and key lengths, directly preventing use of inadequate encryption strength.

SC-12 governs cryptographic key establishment and management, which can enforce sufficient key sizes and thereby reduce inadequate encryption strength.

Requiring protection of transmitted confidentiality and integrity forces selection of sufficiently strong negotiated algorithms rather than weaker ones.

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-01 partial match
prevents

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

PR.AA-04 none match
prevents

PR.AA-04 addresses protection/verification of identity assertions in SSO/federation contexts while CWE-757 concerns protocol-level crypto algorithm negotiation, so the control neither prevents nor meaningfully mitigates the weakness.

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.

finds

Security testing can detect and block algorithm downgrade vulnerabilities before deployment.

mitigates

Ensures network services use secure cryptographic parameters, reducing downgrade risk.

prevents

Requiring the organization to define and enforce minimum cryptographic strength prevents deployment of insufficient key lengths or weak ciphers that can be brute-forced.

prevents

Secure SDLC practices include selecting strong crypto algorithms during design and implementation.

prevents

Application security requirements can specify minimum cryptographic strength to avoid downgrades.

prevents

Secure architecture principles include enforcing strong algorithm selection in protocol design.

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 9 (1 rule)
  • 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 (1 rule)
  • 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
RHEL 9 (1 rule)
  • 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 10 (1 rule)
  • V-220938 The LanMan authentication level must be set to send NTLMv2 response only, and to refuse LM and NTLM. prevents CWE-757
Windows 11 (1 rule)
  • V-253462 The LanMan authentication level must be set to send NTLMv2 response only, and to refuse LM and NTLM. prevents CWE-757
Windows Server 2016 (2 rules)
  • V-225054 The LAN Manager authentication level must be set to send NTLMv2 response only and to refuse LM and NTLM. prevents CWE-757
  • 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
Windows Server 2019 (1 rule)
  • V-205919 Windows Server 2019 LAN Manager authentication level must be configured to send NTLMv2 response only and to refuse LM and NTLM. prevents CWE-757
Windows Server 2022 (1 rule)
  • V-254475 Windows Server 2022 LAN Manager authentication level must be configured to send NTLMv2 response only and to refuse LM and NTLM. prevents CWE-757

References