Re: A CGI application vulnerability for PHP, Go, Python and others

[Solar Designer <solar () openwall com>]

On Tue, Jul 19, 2016 at 02:00:53AM +1200, Richard Rowe wrote:
> The Apache Software Foundation have an advisory available at
> https://www.apache.org/security/asf-httpoxy-response.txt

Neither the Apache advisory above nor the httpoxy website currently
mention the below detail, so I thought I'd post:

Apache httpd trunk's suexec wrapper was patched to filter out HTTP_PROXY
on February 13, 2015:

http://mail-archives.apache.org/mod_mbox/httpd-cvs/201502.mbox/%3C20150213232410.B89BCAC0110 () hades apache org%3E
http://svn.apache.org/r1659711
https://svn.apache.org/repos/asf/httpd/httpd/trunk/CHANGES

  *) suexec: Filter out the HTTP_PROXY environment variable because it is
     treated as alias for http_proxy by some programs. [Stefan Fritsch]

The httpoxy website refers to a posting by Stefan Fritsch:

http://mail-archives.apache.org/mod_mbox/httpd-dev/201502.mbox/%3C2651807.jIIY3NPtlf@k%3E

but not yet to its apparent outcome, above.

httpd 2.4.23's suexec does not yet include this change (different branch).

Of course, it's just suexec, which isn't always used, so it was not a
complete fix anyway.

Alexander