diff options
| -rw-r--r-- | src/ejabberd_c2s.erl | 14 |
1 files changed, 13 insertions, 1 deletions
diff --git a/src/ejabberd_c2s.erl b/src/ejabberd_c2s.erl index 975f79423..383823ace 100644 --- a/src/ejabberd_c2s.erl +++ b/src/ejabberd_c2s.erl @@ -321,7 +321,19 @@ wait_for_stream({xmlstreamstart, #xmlel{ns = NS} = Opening}, StateData) -> Server = binary_to_list(ServerB), case ?IS_MY_HOST(Server) of true -> - Lang = exmpp_stream:get_lang(Opening), + Lang = case exmpp_stream:get_lang(Opening) of + Lang1 when is_binary(Lang1) andalso size(Lang1) =< 35 -> + %% As stated in BCP47, 4.4.1: + %% Protocols or specifications that + %% specify limited buffer sizes for + %% language tags MUST allow for + %% language tags of at least 35 characters. + Lang1; + _ -> + %% Do not store long language tag to + %% avoid possible DoS/flood attacks + undefined + end, change_shaper(StateData, exmpp_jid:make(ServerB)), case exmpp_stream:get_version(Opening) of |