Exim 4 before 4.94.2 allows Use After Free in smtp_reset in certain situations that may be common for builds with OpenSSL.
www.openwall.com/lists/oss-security/2021/05/11/14
www.openwall.com/lists/oss-security/2021/05/11/15
www.openwall.com/lists/oss-security/2021/05/11/17
www.openwall.com/lists/oss-security/2021/05/11/5
www.openwall.com/lists/oss-security/2021/05/11/6
www.openwall.com/lists/oss-security/2021/05/12/2
www.openwall.com/lists/oss-security/2021/05/12/3
www.exim.org/static/doc/security/CVE-2020-qualys/CVE-2020-28018-OCORK.txt