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diff --git a/zarb-ml/mageia-dev/2011-October/008613.html b/zarb-ml/mageia-dev/2011-October/008613.html new file mode 100644 index 000000000..75c6509a2 --- /dev/null +++ b/zarb-ml/mageia-dev/2011-October/008613.html @@ -0,0 +1,133 @@ +<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2//EN"> +<HTML> + <HEAD> + <TITLE> [Mageia-dev] About syslinux & libpng + </TITLE> + <LINK REL="Index" HREF="index.html" > + <LINK REL="made" HREF="mailto:mageia-dev%40mageia.org?Subject=Re%3A%20%5BMageia-dev%5D%20About%20syslinux%20%26%20libpng&In-Reply-To=%3C1317650316.2489.13.camel%40akroma.ephaone.org%3E"> + <META NAME="robots" CONTENT="index,nofollow"> + <META http-equiv="Content-Type" content="text/html; charset=us-ascii"> + <LINK REL="Previous" HREF="008618.html"> + <LINK REL="Next" HREF="008619.html"> + </HEAD> + <BODY BGCOLOR="#ffffff"> + <H1>[Mageia-dev] About syslinux & libpng</H1> + <B>Michael Scherer</B> + <A HREF="mailto:mageia-dev%40mageia.org?Subject=Re%3A%20%5BMageia-dev%5D%20About%20syslinux%20%26%20libpng&In-Reply-To=%3C1317650316.2489.13.camel%40akroma.ephaone.org%3E" + TITLE="[Mageia-dev] About syslinux & libpng">misc at zarb.org + </A><BR> + <I>Mon Oct 3 15:58:36 CEST 2011</I> + <P><UL> + <LI>Previous message: <A HREF="008618.html">[Mageia-dev] freeglut vs. mesa (devel requires problem) +</A></li> + <LI>Next message: <A HREF="008619.html">[Mageia-dev] About syslinux & libpng +</A></li> + <LI> <B>Messages sorted by:</B> + <a href="date.html#8613">[ date ]</a> + <a href="thread.html#8613">[ thread ]</a> + <a href="subject.html#8613">[ subject ]</a> + <a href="author.html#8613">[ author ]</a> + </LI> + </UL> + <HR> +<!--beginarticle--> +<PRE>Le jeudi 29 septembre 2011 à 20:41 +0200, Erwan Velu a écrit : +><i> Le 28/09/2011 22:13, D.Morgan a écrit : +</I>><i> > On Wed, Sep 28, 2011 at 9:56 PM, Erwan Velu<<A HREF="https://www.mageia.org/mailman/listinfo/mageia-dev">erwanaliasr1 at gmail.com</A>> wrote: +</I>><i> >> I'm currently updating Syslinux 4.04 and I'm currently facing a trouble as, +</I>><i> >> historically speaking, we do remove the included libpng by the system one. +</I>><i> >> +</I>><i> >> The compilation process fails. I was wondering if we really consider +</I>><i> >> replacing the libpng of syslinux as a security issue. +</I>><i> >> +</I>><i> >> Sec team ? What's your opinion on it ? +</I>><i> >> +</I>><i> >> Cheers, +</I>><i> >> +</I>><i> > hi, +</I>><i> > +</I>><i> > i take my security hat on, we prefer when possible when we use the system libs. +</I>><i> > i have not looked but which libpng is included ? +</I>><i> +</I>><i> It take the libpng-source to replace the current syslinux code. +</I>><i> +</I>><i> The point is syslinux is a bootloader that obviously don't share libs +</I>><i> with the rest of the system. +</I>><i> Considering that we can attack the bootloader via a picture means you +</I>><i> compromized the picture. If you can change the picture located at /boot, +</I>><i> means that you can compromize the booting parameters too. +</I> +No, that's not the way it work. + +The problem by bundling libpng is the following : +- imagine there is a security issue in libpng ( like it did in the past, +and like it happened on libz, or others ). Let's suppose also the +problem is a simple buffer overflow. So using this buffer overflow, +someone reading a image would trigger the error, who could be crafted to +erase the stack, and inject code in the process. + +So if the error is not fixed, I can simply say on irc : "oh, here is a +picture of a cute duck on <A HREF="http://example.org/~misc/duck.png">http://example.org/~misc/duck.png</A>". You +download, you execute my code, you have lost. + +But since the libpng would be fixed, this would not work. Except that we +cannot garantee that it is fixed everywhere. + +Except if I start to replace this by "here is a nice syslinux boot image +with a duck". And then my code is run by syslinux, just because someone +took my png picture. + +So no, bundling is not without causing trouble. + +><i> So if we take this road of removing bootloader's libs, shall we also +</I>><i> remove the jpeg/gz/gcc/... libs too, and maybe for other bootloaders too ? +</I> +><i> I do understand the need for the application that runs under linux... +</I>><i> but about the bootloaders... +</I> +Unless I am wrong, a bootloader run on ring 0 or can even ( like xen ) +be used to run the kernel in a specific separate memory space ( ie, +virtualisation ). This could open a whole new range of problem ( like +the Blue Pill concept code published 5 years ago by Joanna Rutkowska ) + +So I think that bootloader requires more consideration than regular +application. + +><i> What's your thoughts about it ? +</I>><i> Would you agree on keep syslinux untouched regarding the png lib ? +</I> +For reasons explained before, I would rather disagree. + + +-- +Michael Scherer + +</PRE> + + + + + + + + +<!--endarticle--> + <HR> + <P><UL> + <!--threads--> + <LI>Previous message: <A HREF="008618.html">[Mageia-dev] freeglut vs. mesa (devel requires problem) +</A></li> + <LI>Next message: <A HREF="008619.html">[Mageia-dev] About syslinux & libpng +</A></li> + <LI> <B>Messages sorted by:</B> + <a href="date.html#8613">[ date ]</a> + <a href="thread.html#8613">[ thread ]</a> + <a href="subject.html#8613">[ subject ]</a> + <a href="author.html#8613">[ author ]</a> + </LI> + </UL> + +<hr> +<a href="https://www.mageia.org/mailman/listinfo/mageia-dev">More information about the Mageia-dev +mailing list</a><br> +</body></html> |