Incorrect Type Conversion or Cast Affecting openssl package, versions <1:1.0.2k-21.el7_7.1

Note: Versions mentioned in the description apply only to the upstream openssl package and not the openssl package as distributed by RHEL. See How to fix? for RHEL:7 relevant fixed versions and status.

There is a type confusion vulnerability relating to X.400 address processing inside an X.509 GeneralName. X.400 addresses were parsed as an ASN1_STRING but the public structure definition for GENERAL_NAME incorrectly specified the type of the x400Address field as ASN1_TYPE. This field is subsequently interpreted by the OpenSSL function GENERAL_NAME_cmp as an ASN1_TYPE rather than an ASN1_STRING.

When CRL checking is enabled (i.e. the application sets the X509_V_FLAG_CRL_CHECK flag), this vulnerability may allow an attacker to pass arbitrary pointers to a memcmp call, enabling them to read memory contents or enact a denial of service. In most cases, the attack requires the attacker to provide both the certificate chain and CRL, neither of which need to have a valid signature. If the attacker only controls one of these inputs, the other input must already contain an X.400 address as a CRL distribution point, which is uncommon. As such, this vulnerability is most likely to only affect applications which have implemented their own functionality for retrieving CRLs over a network.

• https://access.redhat.com/security/cve/CVE-2023-0286
• https://www.openssl.org/news/secadv/20230207.txt
• https://ftp.openbsd.org/pub/OpenBSD/LibreSSL/libressl-3.6.2-relnotes.txt
• https://ftp.openbsd.org/pub/OpenBSD/patches/7.2/common/018_x509.patch.sig
• https://git.openssl.org/gitweb/?p=openssl.git;a=commitdiff;h=2c6c9d439b484e1ba9830d8454a34fa4f80fdfe9
• https://git.openssl.org/gitweb/?p=openssl.git;a=commitdiff;h=2f7530077e0ef79d98718138716bc51ca0cad658
• https://git.openssl.org/gitweb/?p=openssl.git;a=commitdiff;h=fd2af07dc083a350c959147097003a14a5e8ac4d
• https://security.gentoo.org/glsa/202402-08