diff --git a/ChangeLog b/ChangeLog
index bcceebb7d..917c521cc 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -6,6 +6,14 @@ New deprecations
    * Deprecate MBEDTLS_SSL_HW_RECORD_ACCEL that enables function hooks in the
      SSL module for hardware acceleration of individual records.
 
+Security
+   * Fix issue in DTLS handling of new associations with the same parameters
+     (RFC 6347 section 4.2.8): an attacker able to send forged UDP packets to
+     the server could cause it to drop established associations with
+     legitimate clients, resulting in a Denial of Service. This could only
+     happen when MBEDTLS_SSL_DTLS_CLIENT_PORT_REUSE was enabled in config.h
+     (which it is by default).
+
 Bugfix
    * Fix compilation failure when both MBEDTLS_SSL_PROTO_DTLS and
      MBEDTLS_SSL_HW_RECORD_ACCEL are enabled.
diff --git a/library/ssl_msg.c b/library/ssl_msg.c
index 18fa55574..a0009d956 100644
--- a/library/ssl_msg.c
+++ b/library/ssl_msg.c
@@ -3197,16 +3197,17 @@ static int ssl_check_dtls_clihlo_cookie(
  * that looks like a ClientHello.
  *
  * - if the input looks like a ClientHello without cookies,
- *   send back HelloVerifyRequest, then
- *   return MBEDTLS_ERR_SSL_HELLO_VERIFY_REQUIRED
+ *   send back HelloVerifyRequest, then return 0
  * - if the input looks like a ClientHello with a valid cookie,
  *   reset the session of the current context, and
  *   return MBEDTLS_ERR_SSL_CLIENT_RECONNECT
  * - if anything goes wrong, return a specific error code
  *
- * mbedtls_ssl_read_record() will ignore the record if anything else than
- * MBEDTLS_ERR_SSL_CLIENT_RECONNECT or 0 is returned, although this function
- * cannot not return 0.
+ * This function is called (through ssl_check_client_reconnect()) when an
+ * unexpected record is found in ssl_get_next_record(), which will discard the
+ * record if we return 0, and bubble up the return value otherwise (this
+ * includes the case of MBEDTLS_ERR_SSL_CLIENT_RECONNECT and of unexpected
+ * errors, and is the right thing to do in both cases).
  */
 static int ssl_handle_possible_reconnect( mbedtls_ssl_context *ssl )
 {
@@ -3237,7 +3238,7 @@ static int ssl_handle_possible_reconnect( mbedtls_ssl_context *ssl )
          * If the error is permanent we'll catch it later,
          * if it's not, then hopefully it'll work next time. */
         (void) ssl->f_send( ssl->p_bio, ssl->out_buf, len );
-        ret = 0;
+        return( 0 );
     }
 
     if( ret == 0 )