Re: remote DoS in Mozilla 1.0

[Stijn Jonker <SJCJonker () SJC nl>]

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Hello all,

The one think that keeps popping up in my mind after reading your post:

Is this really a mozilla bug? 

My answer:

No, because try and font of the size 1666666px in gimp on the same system, 
the symptoms and the end effect is exactly the same here.

System: RH 7.3
        512 M memory
        1024M Swap
        Xfs & XFree86 4.2.0

What happens is that XFS consumes huge amounts of ram, and finally bails 
out. So end of story for the fonts in X. As a result X is practicly 
useless.

I can only guess what happens when you don't use XFS but Xserver based 
fontrendering, the X server consumes huge amounts of mem and cpu and bails 
out => server crash => Bye Bye X.

The solution(s):
        (a) Fix every app to disallow font sizes bigger then <maxvalue>
        (b) Fix XFS to return an error code to the calling application 
when requested font size is greater then configured <maxvalue>

Personally i would go for b.

Just my $0.02, but is you disagree please let me know.

On Mon, 10 Jun 2002, Tom wrote:

> Author            
> ======
> Tom Vogt <tom () lemuria org>
> http://web.lemuria.org/
>
> Affected
> ========
> Mozilla 1.0 and earlier
> verified on Linux and Solaris, other Unixes most likely affected as well.
>
> Effect
> ======
> System becomes unuseable or X windows crashes 
> (varies depending on system configuration)
>
> Description
> ===========
> When loading pages with a specially prepared (or erroneous) stylesheet,
> mozilla and X windows (not restricted to XFree) exhibit any of two 

<<SNIP>> 

> Example
> =======
> Include a huge font size in your style sheet definition, e.g.:
> body { font-size: 1666666px; }

- -- 
Met Vriendelijke groet/Yours Sincerely
Stijn Jonker <SJCJonker () sjc nl>

- --
Outlook Express is actually an incredibly effective virus distribution system which only pretends to be an email 
program.
[by Eric Lee]
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