Answer in brief
CVE-2023-6237 records a Medium severity (CVSS 5.9) vulnerability in Excessive time spent checking invalid RSA public keys. The current sources do not mark it as known exploited. The current feed maps OpenSSL/OpenSSL (generic), Siemens/SIMATIC S7-1500 TM MFP - GNU/Linux subsystem (generic), Siemens/SINEC NMS (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 5.9. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps OpenSSL/OpenSSL (generic), Siemens/SIMATIC S7-1500 TM MFP - GNU/Linux subsystem (generic), Siemens/SINEC NMS (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| OpenSSL/OpenSSLgeneric | >=3.0.0 <3.0.13 || >=3.1.0 <3.1.5 || >=3.2.0 <3.2.1 | 3.0.13, 3.1.5, 3.2.1 |
| Siemens/SIMATIC S7-1500 TM MFP - GNU/Linux subsystemgeneric | >=0 <V1.1.1 | V1.1.1 |
| Siemens/SINEC NMSgeneric | >=0 <V3.0 SP1 | V3.0 SP1, V3.0 |
Published upstream
Apr 25, 2024
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Oct 14, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Oct 14, 2026
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 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.
Quoted source text, attributed separately from HOL analysis.