It was discovered that pyOpenSSL incorrectly handled memory when performing operations on a PKCS #12 store. A remote attacker could possibly use this issue to cause pyOpenSSL to consume resources, resulting in a denial of service.
This attack appear to be exploitable via Depends upon calling application, however it could be as simple as initiating a TLS connection that would cause the calling application to reload certificates from a PKCS #12 store. This vulnerability appears to have been fixed in 17.5.0.
lists.opensuse.org/opensuse-security-announce/2019-04/msg00014.html
access.redhat.com/errata/RHSA-2019:0085
github.com/advisories/GHSA-2rcm-phc9-3945
github.com/pyca/pyopenssl/commit/e73818600065821d588af475b024f4eb518c3509
github.com/pyca/pyopenssl/pull/723
nvd.nist.gov/vuln/detail/CVE-2018-1000808
usn.ubuntu.com/3813-1/