← Vulnerability feed

Vulnerability record · CVE-2023-6237 · published 25 April 2024

CVE-2023-6237: Openssl vulnerability

OOpenssl · Openssl

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.

5.9 CVSS 3.1 Medium EPSS 2.6% · top 14.3% CWE-606 · CWE-606
5.9CVSS 3.1 base score
2.6%EPSS exploitation probability, 30 days
NoNot in CISA KEV
33Affected product versions listed by NVD
14References
10 Nov 2026Last modified by NVD

Description

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:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected products

33 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://github.com/openssl/openssl/commit/0b0f7abfb37350794a4b8960fafc292cd5d1b84d Patch
https://github.com/openssl/openssl/commit/18c02492138d1eb8b6548cb26e7b625fb2414a2a Patch
https://github.com/openssl/openssl/commit/a830f551557d3d66a84bbb18a5b889c640c36294 Patch
https://www.openssl.org/news/secadv/20240115.txt Vendor Advisory
http://www.openwall.com/lists/oss-security/2024/03/11/1 Mailing ListThird Party Advisory
https://github.com/openssl/openssl/commit/0b0f7abfb37350794a4b8960fafc292cd5d1b84d Patch
https://github.com/openssl/openssl/commit/18c02492138d1eb8b6548cb26e7b625fb2414a2a Patch
https://github.com/openssl/openssl/commit/a830f551557d3d66a84bbb18a5b889c640c36294 Patch
https://security.netapp.com/advisory/ntap-20240531-0007/ Third Party Advisory
https://www.openssl.org/news/secadv/20240115.txt Vendor Advisory
https://cert-portal.siemens.com/productcert/html/ssa-265688.html Third Party Advisory
https://cert-portal.siemens.com/productcert/html/ssa-331112.html Third Party Advisory
https://cert-portal.siemens.com/productcert/html/ssa-769027.html Third Party Advisory
https://cert-portal.siemens.com/productcert/html/ssa-915275.html Third Party Advisory

Track CVE-2023-6237 inside VULONE

Watch it alongside the ransomware crews, C2 infrastructure and forum chatter that reference it, query it through the API and pull it into your SIEM over TAXII.

Start free Open in platform

Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

7.8CVE-2024-1086Linux kernel nf_tables use-after-free allows local privilege escalationThe Linux kernel's netfilter nf_tables component has a use-after-free in nft_verdict_init(), where positive drop errors are accepted and nf_hook_slow…KEVEPSS 28%analysed7.0CVE-2021-22600Linux kernel af_packet double free allows local privilege escalationA double free bug in packet_set_ring() in net/packet/af_packet.c lets a local user trigger memory corruption through crafted syscalls. It matters bec…KEVEPSS 6.6%analysed9.8CVE-2024-4741Openssl use after free vulnerabilityIssue summary: Calling the OpenSSL API function SSL_free_buffers may cause memory to be accessed that was previously freed in some situations Impact …EPSS 3.3%9.1CVE-2024-5535Openssl out-of-bounds read vulnerabilityIssue summary: Calling the OpenSSL API function SSL_select_next_proto with an empty supported client protocols buffer may cause a crash or memory con…EPSS 6.1%8.8CVE-2024-9143Openssl out-of-bounds read vulnerabilityIssue summary: Use of the low-level GF(2^m) elliptic curve APIs with untrusted explicit values for the field polynomial can lead to out-of-bounds mem…EPSS 12%8.1CVE-2024-6387OpenSSH sshd signal handler race condition allows unauthenticated remote code executionA security regression of CVE-2006-5051 in OpenSSH's sshd creates a race condition where signals are handled unsafely. An unauthenticated remote attac…EPSS 100%analysed8.1CVE-2020-8625BIND GSS-TSIG buffer overflow in namedBIND's named process contains a classic buffer overflow (CWE-120) reachable when GSS-TSIG is enabled via the tkey-gssapi-keytab or tkey-gssapi-creden…EPSS 65%analysed8.1CVE-2020-14305Linux kernel out-of-bounds write vulnerabilityAn out-of-bounds memory write flaw was found in how the Linux kernel’s Voice Over IP H.323 connection tracking functionality handled connections on i…EPSS 5.2%

Source: NIST National Vulnerability Database (record CVE-2023-6237), CISA KEV, FIRST EPSS (scores of 2026-11-12). This page is refreshed as NVD updates the record.