Re: REPL Server: Guard against HTTP inter-protocol exploitation attacks.

[Alex Kost]

Ludovic Courtès (2016-10-12 14:23 +0200) wrote:

> Alex Kost <address@hidden> skribis:
>
>> Hello, I've noticed an insignificant typo in commit
>> 08c021916dbd3a235a9f9cc33df4c418c0724e03 (in the fancy warning message).
>>
>> [...]
>>> +               ;; Print a report to STDERR (POSIX file descriptor 2).
>>> +               ;; XXX Can we do better here?
>>> +               (call-with-port (dup->port 2 "w")
>>> +                 (cut format <> "
>>> +@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
>>> +@@ POSSIBLE BREAK-IN ATTEMPT ON THE REPL SERVER                @@
>>> +@@ BY AN HTTP INTER-PROTOCOL EXPLOITATION ATTACK.  See:        @@
>>> +@@ <https://en.wikipedia.org/wiki/Inter-protocol_exploitation> @@
>>> +@@ Possible HTTP request received: ~S
>>                                                                   ^^
>> Missing trailing "@@" in the above line.
>
> As discussed on IRC, I think this is intended: we don’t know the length
> of the string being printed by ~S.

Yes, I got it, thanks and sorry for bothering :-)

-- 
Alex