--- a/time/unix/time.c  2017/09/10 22:11:37 1807974
+++ b/time/unix/time.c  2017/09/10 22:30:14 1807975
@@ -142,6 +142,9 @@
     static const int dayoffset[12] =
     {306, 337, 0, 31, 61, 92, 122, 153, 184, 214, 245, 275};
 
+    if (xt->tm_mon < 0 || xt->tm_mon >= 12)
+        return APR_EBADDATE;
+
     /* shift new year to 1st March in order to make leap year calc easy */
 
     if (xt->tm_mon < 2)