general/2819: errors detected when parsing the headers aren't sent to the client

[Tony Finch <fa...@demon.net>]

>Number:         2819
>Category:       general
>Synopsis:       errors detected when parsing the headers aren't sent to the client
>Confidential:   no
>Severity:       non-critical
>Priority:       medium
>Responsible:    apache
>State:          open
>Class:          sw-bug
>Submitter-Id:   apache
>Arrival-Date:   Mon Aug 10 09:40:00 PDT 1998
>Last-Modified:
>Originator:     fanf@demon.net
>Organization:
apache
>Release:        1.3.1
>Environment:
I found the error when hacking 1.3b3 on Solaris 2.6, but the same problem
exists in 1.3.1 as is obvious from a code inspection.
>Description:
get_mime_headers() in src/main/http_protocol.c can generate errors, e.g.
when a malformed header (without a colon) or when too many headers are
supplied if you have patched it against the recent denail of service attack.
In this situation, the error is collected in a buffer but the buffer is not
flushed. This is because the flushing is usually left to child_main() in
src/main/http_main.c, but child_main() only does this if read_request()
returns non-NULL, which is not the case when get_mime_headers() causes an
error.
>How-To-Repeat:
$ telnet localhost http
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
GET / HTTP/1.0
foo
bar
Connection closed by foreign host.
$
>Fix:
add
	ap_bflush(r->connection->client);
before the error return from get_mime_headers().
>Audit-Trail:
>Unformatted:
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