diff --git a/library/x509_crl.c b/library/x509_crl.c
index 8450f87..64fac0e 100644
--- a/library/x509_crl.c
+++ b/library/x509_crl.c
@@ -103,6 +103,9 @@
 {
     int ret;
 
+    if( *p == end )
+        return( 0 );
+
     /*
      * crlExtensions           [0]  EXPLICIT Extensions OPTIONAL
      *                              -- if present, version MUST be v2
@@ -115,6 +118,8 @@
         return( ret );
     }
 
+    end = ext->p + ext->len;
+
     while( *p < end )
     {
         /*