The issue arises from the improper handling of NULL fields in PKCS12 files, leading to a potential Denial of Service attack. Applications loading files in the PKCS12 format from untrusted sources might terminate abruptly due to a NULL pointer dereference. The affected OpenSSL APIs are: `PKCS12 parse()`, `PKCS12 unpack p7data()`, `PKCS12 unpack p7encdata()`, `PKCS12 unpack authsafes()`, and `PKCS12 newpass()`.