From: Eric Wong <e@80x24.org>
To: meta@public-inbox.org
Subject: [PATCH] httpd: reject requests with spaces in header names
Date: Tue, 19 Oct 2021 21:26:15 +0000 [thread overview]
Message-ID: <20211019212615.16341-1-e@80x24.org> (raw)
Malicious clients may attempt HTTP request smuggling this way.
This doesn't affect our current code as we only look for exact
matches, but it could affect other servers behind a
to-be-implemented reverse proxy built around our -httpd.
This doesn't affect users behind varnish at all, nor the
HTTPS/HTTP reverse proxy I use (I don't know about nginx), but
could be passed through by other reverse proxies.
This change is only needed for HTTP::Parser::XS which most users
probably use. Users of the pure Perl parser (via
PLACK_HTTP_PARSER_PP=1) already hit 400 errors in this case,
so this makes the common XS case consistent with the pure Perl
case.
cf. https://www.mozilla.org/en-US/security/advisories/mfsa2006-33/
---
lib/PublicInbox/HTTP.pm | 1 +
t/httpd-corner.t | 7 ++++++-
2 files changed, 7 insertions(+), 1 deletion(-)
diff --git a/lib/PublicInbox/HTTP.pm b/lib/PublicInbox/HTTP.pm
index 0f4b5047..18a19250 100644
--- a/lib/PublicInbox/HTTP.pm
+++ b/lib/PublicInbox/HTTP.pm
@@ -91,6 +91,7 @@ sub event_step { # called by PublicInbox::DS
}
$self->do_read($rbuf, 8192, length($$rbuf)) or return;
}
+ return quit($self, 400) if grep(/\s/, keys %env); # stop smugglers
$$rbuf = substr($$rbuf, $r);
my $len = input_prepare($self, \%env) //
return write_err($self, undef); # EMFILE/ENFILE
diff --git a/t/httpd-corner.t b/t/httpd-corner.t
index cec754c9..0a613a9e 100644
--- a/t/httpd-corner.t
+++ b/t/httpd-corner.t
@@ -82,7 +82,12 @@ if ('test worker death') {
like($body, qr/\A[0-9]+\z/, '/pid response');
isnt($body, $pid, 'respawned worker');
}
-
+{
+ my $conn = conn_for($sock, 'Header spaces bogus');
+ $conn->write("GET /empty HTTP/1.1\r\nSpaced-Out : 3\r\n\r\n");
+ $conn->read(my $buf, 4096);
+ like($buf, qr!\AHTTP/1\.[0-9] 400 !, 'got 400 response on bad request');
+}
{
my $conn = conn_for($sock, 'streaming callback');
$conn->write("GET /callback HTTP/1.0\r\n\r\n");
reply other threads:[~2021-10-19 21:26 UTC|newest]
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