Exim -- remote code execution and information disclosure

Release notes for Exim 4.76 says:

Bugzilla 1106: CVE-2011-1764 - DKIM log line was subject to
a format-string attack – SECURITY: remote arbitrary code
execution.
DKIM signature header parsing was double-expanded, second
time unintentionally subject to list matching rules, letting
the header cause arbitrary Exim lookups (of items which can
occur in lists, not arbitrary string expansion). This
allowed for information disclosure.

Also, impact assessment was redone shortly after the original
announcement:

Further analysis revealed that the second security was
more severe than I realised at the time that I wrote the
announcement. The second security issue has been assigned
CVE-2011-1407 and is also a remote code execution flaw.
For clarity: both issues were introduced with 4.70.