Re: [PATCH 1/1] gnu: libupnp: Fix CVE-2016-6255.

[ludo@gnu.org (Ludovic Courtès)]

Leo Famulari <leo@famulari.name> skribis:

> * gnu/packages/patches/libupnp-CVE-2016-6255.patch: New file.
> * gnu/local.mk (dist_patch_DATA): Add it.
> * gnu/packages/libupnp.scm (libupnp): Use it.

[...]

> +From d64d6a44906b5aa5306bdf1708531d698654dda5 Mon Sep 17 00:00:00 2001
> +From: Matthew Garrett <mjg59@srcf.ucam.org>
> +Date: Tue, 23 Feb 2016 13:53:20 -0800
> +Subject: [PATCH] Don't allow unhandled POSTs to write to the filesystem by
> + default
> +
> +If there's no registered handler for a POST request, the default behaviour
> +is to write it to the filesystem. Several million deployed devices appear
> +to have this behaviour, making it possible to (at least) store arbitrary
> +data on them. Add a configure option that enables this behaviour, and change
> +the default to just drop POSTs that aren't directly handled.

Fun.  :-)

> +diff --git a/configure.ac b/configure.ac
> +index 9548913..a8731b5 100644
> +--- a/configure.ac
> ++++ b/configure.ac

Shouldn’t it require an autoreconf phase?

I would suggest shrinking this patch to just:

> +--- a/upnp/src/genlib/net/http/webserver.c
> ++++ b/upnp/src/genlib/net/http/webserver.c
> +@@ -1367,9 +1367,13 @@ static int http_RecvPostMessage(
> + 		if (Fp == NULL)
> + 			return HTTP_INTERNAL_SERVER_ERROR;
> + 	} else {
> ++#ifdef UPNP_ENABLE_POST_WRITE
> + 		Fp = fopen(filename, "wb");
> + 		if (Fp == NULL)
> + 			return HTTP_UNAUTHORIZED;
> ++#else
> ++		return HTTP_NOT_FOUND;
> ++#endif

… with “#if 0” instead of “#ifdef UPNP_ENABLE_POST_WRITE”.

WDYT?

Feel free to commit adjusted as you see fit!

Thanks,
Ludo’.