[klibc] [oss-security] CVE request: klibc: ipconfig sh script with unescaped DHCP options

Dan Rosenberg dan.j.rosenberg at gmail.com
Wed May 18 13:41:29 PDT 2011


On Wed, May 18, 2011 at 4:29 PM, maximilian attems <max at stro.at> wrote:
> On Wed, May 18, 2011 at 04:13:05PM -0400, Dan Rosenberg wrote:
>> Might it be worth fixing the insecure temporary file usage?
>>
>> 122         snprintf(fn, sizeof(fn), "/tmp/net-%s.conf", dev->name);
>> 123         f = fopen(fn, "w");
>>
>> What if someone else has already created that file, or put a symlink
>> or hard link there?
>
> for the initramfs case I don't see how.
> outside of initramfs usage I'd agree that this needs fixing.
>

Right, this only applies after boot is done.

>> What if someone overwrites your string with
>> command injection characters despite your stripping?
>
> please be more verbose, what example do you have in mind?
>

Sorry for not being clear.  If you're concerned about scripts parsing
this file while it has command injection strings in it, what's to stop
someone from putting a malicious file there if one doesn't already
exist?  It sounds like the scripts that depend on this file should
probably be fixed here, or the file itself should be moved to a
location where it's not writable by unprivileged users.

-Dan

> thank you for the review.
>
> --
> maks
>
>



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