Cyber Resilience

CVE-2023-6237

Published
25 April 2024
Modified
12 May 2026
CVSS Score v3.1 5.9
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS Score 0.023 82th percentile
Risk Priority 50 floored blend · peak EPSS

Summary

CVE-2023-6237 is a medium-severity Unchecked Input for Loop Condition (CWE-606) vulnerability in Siemens (inferred from references). Its CVSS base score is 5.9 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Application or System Exploitation (T1499.004); ranked in the top 18% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SI-10 (Information Input Validation) — see the control section below for these in your framework.

EU & UK References

Vulnerability Data

Issue summary: Checking excessively long invalid RSA public keys may take a long time. Impact summary: Applications that use the function EVP_PKEY_public_check() to check RSA public keys may experience long delays. Where the key that is being checked has been…

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obtained from an untrusted source this may lead to a Denial of Service. When function EVP_PKEY_public_check() is called on RSA public keys, a computation is done to confirm that the RSA modulus, n, is composite. For valid RSA keys, n is a product of two or more large primes and this computation completes quickly. However, if n is an overly large prime, then this computation would take a long time. An application that calls EVP_PKEY_public_check() and supplies an RSA key obtained from an untrusted source could be vulnerable to a Denial of Service attack. The function EVP_PKEY_public_check() is not called from other OpenSSL functions however it is called from the OpenSSL pkey command line application. For that reason that application is also vulnerable if used with the '-pubin' and '-check' options on untrusted data. The OpenSSL SSL/TLS implementation is not affected by this issue. The OpenSSL 3.0 and 3.1 FIPS providers are affected by this issue.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1499.004 Application or System Exploitation Impact
Adversaries may exploit software vulnerabilities that can cause an application or system to crash and deny availability to users.
T1499 Endpoint Denial of Service Impact
Adversaries may perform Endpoint Denial of Service (DoS) attacks to degrade or block the availability of services to users.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2025-43801Shared CWE-606
CVE-2026-20301Shared CWE-606
CVE-2026-27689Shared CWE-606
CVE-2025-42930Shared CWE-606
CVE-2024-13930Shared CWE-606
CVE-2026-41986Shared CWE-606
CVE-2024-13931Shared CWE-606
CVE-2026-62901Shared CWE-606
CVE-2026-0243Shared CWE-606
CVE-2024-34486Shared CWE-606

Affected Assets

Siemens
inferred from references and description; NVD did not file a CPE for this CVE

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)

Validate
Prove the fix (OWASP ASVS)
  • V17.3.2
  • V4.3.1

Mitigating Controls (NIST 800-53 r5) AI

Input validation directly stops untrusted values from reaching loop conditions without bounds or sanity checks.

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 require input validation and bounds checking that prevent unchecked loop conditions.

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 in development can detect and block unchecked loop conditions before release.

prevents

Secure development lifecycle requires input validation and bounds checking that can prevent unchecked loop conditions.

prevents

Application security requirements include input validation rules that mitigate excessive looping from untrusted data.

prevents

Secure coding standards directly mandate validation of loop-control inputs to prevent unbounded iteration.

References