http://sourceforge.net/p/net-snmp/code/ci/4c5633f1603e4bd03ed05c37d782ec8911759c47/

diff --git a/agent/mibgroup/agent/extend.c b/agent/mibgroup/agent/extend.c

index 00d270a..cd0b2d6 100644

--- a/agent/mibgroup/agent/extend.c

+++ b/agent/mibgroup/agent/extend.c

@@ -1132,7 +1132,7 @@ _extend_find_entry( netsnmp_request_info       *request,

              * ...and check the line requested is valid

              */

             line_idx = *table_info->indexes->next_variable->val.integer;

-            if (eptr->numlines < line_idx)

+            if (line_idx < 1 || line_idx > eptr->numlines)

                 return NULL;

         }

         return eptr;

@@ -1305,6 +1305,10 @@ handle_nsExtendOutput2Table(netsnmp_mib_handler          *handler,

                  * Determine which line we've been asked for....

                  */

                 line_idx = *table_info->indexes->next_variable->val.integer;

+                if (line_idx < 1 || line_idx > extension->numlines) {

+                    netsnmp_set_request_error(reqinfo, request, SNMP_NOSUCHINSTANCE);

+                    continue;

+                }

                 cp  = extension->lines[line_idx-1];

                 /*