[elinks-users] a url that locks up elinks

Kalle Olavi Niemitalo kon at iki.fi
Sat Sep 19 02:33:15 PDT 2009


John Magolske <b79net at gmail.com> writes:

> Navigating to the following url, I find Elinks hangs indefinitely
> displaying the message "Request sent" with the cpu maxed out at 100%:
>
> http://www.eweek.com/c/a/Application-Development/Google-Delivers-New-Javalike-Language-Noop-473613/

This is ELinks bug 1083, added in 0.12pre3 and fixed after 0.12pre5.
http://bugzilla.elinks.cz/show_bug.cgi?id=1083
http://elinks.cz/release.html

The server at www.eweek.com sends these HTTP headers, among others:

Content-Type: text/html
Content-Encoding: gzip
Transfer-Encoding: chunked

This means the body is HTML compressed with gzip, and the server
is going to send it in chunks so that it needn't compute the
Content-Length up front.  However, the server actually compresses
individual chunks rather than the whole body, and doesn't even
compress all of them.  This violates the HTTP protocol and causes
vulnerable versions of ELinks to fall in an infinite loop.

As a workaround, you can compile ELinks without decompression
support, or disable the protocol.http.compression option.
The latter workaround is not reliable against malicious servers.
For the www.eweek.com server specifically, I think there was
also some User-Agent string that worked around the bug.

If you can find some contact person for the server, it would be
good to get the compression bug fixed at that end.



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