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Re: Environment variable of a name which is often used
From: |
Norihiro Tanaka |
Subject: |
Re: Environment variable of a name which is often used |
Date: |
Sat, 27 Sep 2014 11:18:05 +0900 |
Eric Blake wrote:
> This is a known issue, but NOT necessarily a security bug. In other
> words, it's no worse than running:
>
> env LD_PRELOAD=... ./test.sh
>
> with a malicious preload library. Remember, the security aspect of
> CVE-2014-6271 is that bash does unwanted parsing of the _contents_ of an
> environment variable, and NOT that it is tied to the _name_ of the
> variable. The exploit happens because well-known programs stick
> user-controlled contents into a name already under the program's
> control, and NOT because well-known programs are creating arbitrary
> names in the environment (that is, a vulnerable system running apache is
> NOT creating arbitrary variables, so much as sticking arbitrary contents
> into a variable named HTTP_...).
Thanks. I understood that issue by CVE-2014-6271 is in below.
- bash does unwanted parsing of the _contents_ of an environment variable
- CVE-2014-6271 can be caused by any envoronment variable.
In my case, both conditions aren't filled.