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RE: Re: bzip2 bombs still causes problems in antivirus-software
From: "Dr. Peter Bieringer" <pbieringer () aerasec de>
Date: Mon, 12 Jan 2004 11:22:04 +0100
--On Sonntag, 11. Januar 2004 09:24 +1300 Steve Wray <steve.wray () paradise net nz> wrote:
Dr. Peter Bieringer Steve Wray schreibt: > It would probably be a good idea to implement ulimit > restrictions on the user that the software runs as. Mostly "root"...and this will cause sure other fun, looks like some software didn't expect that file system runs out-of-spaceand stillhang and have no fail-safe mechanism here...If your antivirus software (which, by definition, is routinely exposed to 'malware') runs as root, then you have worse potential issues than just a bzip bomb consuming resources.
You're right, but I'm not very sure that all global filesystem scanners on Linux/Unix (which need normally root permissions to get access on all files - on non-ACL and simple Unix group-usage systems) drop capabilities and/or chroot before decompressing/scanning a file to minimize the risk.
For in-line content scanners of mailsystems or FTP/HTTP running as non-root is hopefully a default.
It's not so nice that customers have to double-check how the products work internally...proper QA should be normally better placed on vendor's side ;-)
But btw: who of the customer cares about such issues in general? Seldom seen, that technical implementation of the antivirus software like e.g.
- daemons running root - daemons/programs not dropping capabilities - how many files have suid root and why - insecure /tmp file handling - insecure permissions on /tmp files and others - insecure web interface (self made or outdated built-in HTTP server) - admin password transfers in cleartext - pattern update process needs root permissions - ...many more... was a real reason for a not-to-buy decission...Because if would...vendors should have already react and provide more secure designed software...
Peter -- Dr. Peter Bieringer Phone: +49-8102-895190 AERAsec Network Services and Security GmbH Fax: +49-8102-895199 Wagenberger Straße 1 Mobile: +49-174-9015046 D-85662 Hohenbrunn E-Mail: pbieringer () aerasec de Germany Internet: http://www.aerasec.de _______________________________________________ Full-Disclosure - We believe in it. Charter: http://lists.netsys.com/full-disclosure-charter.html
Current thread:
- bzip2 bombs still causes problems in antivirus-software Dr. Peter Bieringer (Jan 09)
- RE: bzip2 bombs still causes problems in antivirus-software Steve Wray (Jan 09)
- Re: bzip2 bombs still causes problems in antivirus-software Dr. Peter Bieringer (Jan 10)
- RE: Re: bzip2 bombs still causes problems in antivirus-software Steve Wray (Jan 10)
- RE: Re: bzip2 bombs still causes problems in antivirus-software Dr. Peter Bieringer (Jan 12)
- Re: bzip2 bombs still causes problems in antivirus-software Dr. Peter Bieringer (Jan 10)
- RE: bzip2 bombs still causes problems in antivirus-software Steve Wray (Jan 09)
- Re: bzip2 bombs still causes problems in antivirus-software...probably zip, too Dr. Peter Bieringer (Jan 12)