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.

This vulnerability is classified as low severity because policy processing in OpenSSL is disabled by default, meaning that most deployments are unaffected unless explicitly configured to enable policy checks. Additionally, while the flaw can cause exponential computational resource consumption, it does not allow for remote code execution, memory corruption, or data exfiltration—limiting its impact to a denial-of-service (DoS) condition. Exploiting this issue also requires an attacker to supply a specifically crafted X.509 certificate chain, which is only feasible in scenarios where certificate validation of untrusted chains is performed, further reducing the practical risk.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.