CVE-2023-6237Excessive time spent checking invalid RSA public keys
Updated under an hour ago ()
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It affects OpenSSL and 2 other products. Add what you run to find out whether that includes you.
No exploitation reported and no EPSS estimate yet.
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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.
- CVSS
- 5.9 MEDIUM (v3.1, CISA ADP)CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
- Weakness (CWE)
- CWE-606
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- openssl
- NVD analysis
- Deferred
- Record last updated
- Oct 14, 2026
- First seen by InfoSec Signals
- Oct 14, 2026
Affected products
OpenSSL OpenSSL openssl:openssl (from the name) | from 3.0.0 before 3.0.13; from 3.1.0 before 3.1.5; from 3.2.0 before 3.2.1 | CNA record |
Siemens SIMATIC S7-1500 TM MFP - GNU/Linux subsystem siemens:simatic_s7_1500_tm_mfp_gnu_linux_subsystem (from the name) | before V1.1.1 | CISA ADP |
Siemens SINEC NMS siemens:sinec_nms (from the name) | before V3.0 SP1 | CISA ADP |
References
- https://www.openssl.org/news/secadv/20240115.txtvendor-advisory
- https://github.com/openssl/openssl/commit/18c02492138d1eb8b6548cb26e7b625fb2414a2apatch
- https://github.com/openssl/openssl/commit/a830f551557d3d66a84bbb18a5b889c640c36294patch
- https://github.com/openssl/openssl/commit/0b0f7abfb37350794a4b8960fafc292cd5d1b84dpatch
- http://www.openwall.com/lists/oss-security/2024/03/11/1
- https://security.netapp.com/advisory/ntap-20240531-0007/
- https://cert-portal.siemens.com/productcert/html/ssa-265688.html
- https://cert-portal.siemens.com/productcert/html/ssa-331112.html
- https://cert-portal.siemens.com/productcert/html/ssa-769027.html
- https://cert-portal.siemens.com/productcert/html/ssa-915275.html
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.