CVE-2023-0464

A security vulnerability has been identified in all supported OpenSSL versions related to verifying X.509 certificate chains that include policy constraints. This flaw allows attackers to exploit this vulnerability by creating a malicious certificate chain that triggers exponential use of computational resources, leading to a denial of service (DoS) attack on affected systems. Policy processing is disabled by default but can be enabled by passing the -policy' argument to the command line utilities or calling the X509_VERIFY_PARAM_set1_policies()' function.

A security vulnerability has been identified in all supported versions of OpenSSL related to the verification of X.509 certificate chains that include policy constraints. Attackers may be able to exploit this vulnerability by creating a malicious certificate chain that triggers exponential use of computational resources, leading to a denial-of-service (DoS) attack on affected systems. Policy processing is disabled by default but can be enabled by passing the `-policy' argument to the command line utilities or by calling the `X509_VERIFY_PARAM_set1_policies()' function.

It was discovered that OpenSSL was not properly managing file locks when processing policy constraints. If a user or automated system were tricked into processing a certificate chain with specially crafted policy constraints, a remote attacker could possibly use this issue to cause a denial of service. This issue only affected Ubuntu 22.04 LTS and Ubuntu 22.10. David Benjamin discovered that OpenSSL was not properly performing the verification of X.509 certificate chains that include policy constraints, which could lead to excessive resource consumption. If a user or automated system were tricked into processing a specially crafted X.509 certificate chain that includes policy constraints, a remote attacker could possibly use this issue to cause a denial of service.