Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.

The Libreswan Project was informed of a Null Pointer Dereference bug in the PKCS#7 handling code for authentication that can result in a denial of service against the libreswan pluto daemon. 

When libreswan decodes an IKE CERT payload of type CERT_PKCS7_WRAPPED_X509, it guards the PKCS#7 blob with SEC_PKCS7ContainsCertsOrCrls() and then iterates the certificate list with SEC_PKCS7GetCertificateList(). The two NSS APIs disagree on a SignedData that carries a CRL but no
certificates: ContainsCertsOrCrls() returns PR_TRUE (there is a CRL), so the guard passes, but GetCertificateList() returns NULL (there are no certificates). This causes libreswan to dereference a null pointer leading to a crash and restart.

An malicious IKE_AUTH packet can trigger this bug, meaning the peer need not be authenticated. Continued attempts to use IKEv2 with such malicious payloads can cause a denial of service. No remote code execution is possible.

Vulnerable versions : 4.7 - 5.4
Not vulnerable      : 5.3.3, 5.4.1