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.
{
"license": "CC-BY-4.0",
"sources": [
{
"published": "2024-04-25T07:15:45.270Z",
"imported": "2026-07-17T21:27:56.972Z",
"html_url": "https://nvd.nist.gov/vuln/detail/CVE-2023-6237",
"id": "CVE-2023-6237",
"url": "https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2023-6237",
"modified": "2026-06-17T06:50:21.877Z",
"database_specific": {
"status": "Deferred"
}
},
{
"published": "2024-04-25T09:32:09Z",
"url": "https://api.github.com/advisories/GHSA-hvc4-mjv4-5mw6",
"html_url": "https://github.com/advisories/GHSA-hvc4-mjv4-5mw6",
"id": "GHSA-hvc4-mjv4-5mw6",
"imported": "2026-07-17T21:27:57.117Z",
"modified": "2026-05-12T12:31:42Z"
},
{
"published": "2024-04-25T06:27:26Z",
"url": "https://euvdservices.enisa.europa.eu/api/enisaid?id=EUVD-2023-58483",
"html_url": "https://euvd.enisa.europa.eu/vulnerability/EUVD-2023-58483",
"id": "EUVD-2023-58483",
"imported": "2026-07-17T21:28:07.533Z",
"modified": "2026-05-12T10:41:05Z"
}
]
}