When strict certificate chain checks are enabled (which is not the default configuration) it is possible for an attacker to bypass these checks. X509_V_FLAG_X509_STRICT must be set and either no purpose configured or the default purpose is overriden.
OpenSSL versions 1.1.1h and newer are affected. The fix is available in OpenSSL 1.1.1k.
OpenSSL 1.0.2 is not affected.
GuidanceOrganizations that develop products or services that utilize OpenSSL should integrate the fixes as soon as possible.
Organizations that use products that have embedded OpenSSL should monitor their vendor patch releases to see if they are affected and patch according to your normal priority patch window cycle unless you are running very sensitive applications in need of a very high level of CA assurance (CVE-2021-3450) or have internet-facing systems that could be targeted with hard-to-detect application-level denial-of-service attacks (CVE-2021-3449)
