Re: CVE-2021-3847: OverlayFS - Potential Privilege Escalation using overlays copy_up

Related Vulnerabilities: CVE-2021-3847   CVE-2016-1575   CVE-2016-2853   CVE-2016-1576  
                Alon Zahavi writes:

Just funny, just hours before this mail I got 3 mails on different
overlayfs copy-up vuln, e.g.

"""
The Precise Pangolin has reached end of life, so this bug will not be
fixed for that release

** Changed in: linux (Ubuntu Precise)
       Status: New => Won't Fix

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https://bugs.launchpad.net/bugs/1534961
"""
...

[Bug 1534961] Re: CVE-2016-1575
[Bug 1547400] Re: CVE-2016-2853
[Bug 1535150] Re: CVE-2016-1576

So it is 5 years and not so much changed :-)

Overlayfs and alike where lower privileged user can simultaneously
access lower/upper AND the mounted file system is extremely dangerous
and prone to so many vulns, that nobody should use/allow that.

hd