CVE-2023-0215

The public API function BIO_new_NDEF is a helper function used for
streaming ASN.1 data via a BIO. It is primarily used internally to OpenSSL
to support the SMIME, CMS and PKCS7 streaming capabilities, but may also be
called directly by end user applications. The function receives a BIO from
the caller, prepends a new BIO_f_asn1 filter BIO onto the front of it to
form a BIO chain, and then returns the new head of the BIO chain to the
caller. Under certain conditions, for example if a CMS recipient public key
is invalid, the new filter BIO is freed and the function returns a NULL
result indicating a failure. However, in this case, the BIO chain is not
properly cleaned up and the BIO passed by the caller still retains internal
pointers to the previously freed filter BIO. If the caller then goes on to
call BIO_pop() on the BIO then a use-after-free will occur. This will most
likely result in a crash. This scenario occurs directly in the internal
function B64_write_ASN1() which may cause BIO_new_NDEF() to be called and
will subsequently call BIO_pop() on the BIO. This internal function is in
turn called by the public API functions PEM_write_bio_ASN1_stream,
PEM_write_bio_CMS_stream, PEM_write_bio_PKCS7_stream, SMIME_write_ASN1,
SMIME_write_CMS and SMIME_write_PKCS7. Other public API functions that may
be impacted by this include i2d_ASN1_bio_stream, BIO_new_CMS,
BIO_new_PKCS7, i2d_CMS_bio_stream and i2d_PKCS7_bio_stream. The OpenSSL cms
and smime command line applications are similarly affected.