The dmarc_process function in dmarc.c in Exim before 4.82.1, when EXPERIMENTAL_DMARC is enabled, allows remote attackers to execute arbitrary code via the From header in an email, which is passed to the expand_string function.

expand.c in Exim before 4.83 expands mathematical comparisons twice, which allows local users to gain privileges and execute arbitrary commands via a crafted lookup value.

Heap-based buffer overflow in the dkim_exim_query_dns_txt function in dkim.c in Exim 4.70 through 4.80, when DKIM support is enabled and acl_smtp_connect and acl_smtp_rcpt are not set to "warn control = dkim_disable_verify," allows remote attackers to execute arbitrary code via an email from a malicious DNS server.