oss-sec mailing list archives
Re: chroots & uid sharing
From: Tom Maher <tmaher () heroku com>
Date: Fri, 7 Jun 2013 16:54:16 -0700
On Thu, Jun 6, 2013 at 8:26 PM, Kurt Seifried <kseifried () redhat com> wrote:
I literally can't remember when people started saying "if you're using chroot for security, you're doing it wrong" it was a long time ago. At least a decade for myself and I wasn't the first person (that probably goes to the BSD guys and jail()): http://seclists.org/vuln-dev/2002/May/419
This assertion has always bugged me. Yes, if you are using chroot for security, and only chroot for security, you're absolutely doing it wrong. However, when used with an awareness of its limitations, as you quite rightly point out and enumerate, I argue chroot (and its more sophisticated cousins jail and pivot_root) does in fact provide some defense. For example, think multiple different, mutually-distrusting applications on a host, one of which has a simple directory traversal bug, and the other of which mistakenly has sensitive files set to be world readable (but without any directory traversal issues). chroot is great for that. I would be less bugged by this if I hadn't repeatedly encountered well-intentioned folks who hear that argument and think that chroot is completely useless for security enforcement, rather than simply insufficient. -- Tom Maher <tmaher () heroku com>
Current thread:
- chroots & uid sharing Jason A. Donenfeld (Jun 06)
- Re: chroots & uid sharing Jason A. Donenfeld (Jun 06)
- Re: chroots & uid sharing Seth Arnold (Jun 06)
- Re: chroots & uid sharing Kurt Seifried (Jun 06)
- Re: chroots & uid sharing Tom Maher (Jun 07)
- Re: chroots & uid sharing Kurt Seifried (Jun 06)