I just ran the static analyser "cppcheck" over the source code of certmonger-0.67
It said

[store-gen.c:244]: (error) Buffer is accessed out of bounds.

Source code is

cm_store_timestamp_from_time_for_display(time_t when, char timestamp[21])
{
struct tm tm;
if ((when != 0) && (gmtime_r(&when, &tm) == &tm)) {
sprintf(timestamp, "%04d-%02d-%02d %02d:%02d:%02d UTC",
tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
tm.tm_hour, tm.tm_min, tm.tm_sec);
} else {
strcpy(timestamp, "19700101000000");

I count 25 chars written into timestamp by the first call
to sprintf. Suggest increase 21 in timestamp declaration to 25
and adjust the caller of cm_store_timestamp_from_time_for_display
to suit.

Also, the text in the call to strcpy doesn't match the format
in the call to sprintf.