oss-sec mailing list archives
Re: CVE Request: bash-completion: dequote command injection
From: John Haxby <john.haxby () oracle com>
Date: Thu, 25 Feb 2016 10:53:29 +0000
On 24/02/16 21:58, Kurt Seifried wrote:
I think in this case it's pretty simply "dequoting should not result in code execution" much like the various deserialization flaws (they should deserialize the data, not execute random stuff).
My immediate assumption was that an unprivileged user could leave something lying around that root could complete on. Within bash-completion, most of the uses of dequote are to find a config file so there'd be a degree of social engineering to persuade root to use a config file of your choice. The other main use seems to be in _parse_help() and _parse_usage() which parse gnu-style help and bsd-style usage respectively and that might not need as much social engineering to exploit. I didn't investigate further. Whether or not this turns out to be exploitable at all in bash-completion, I do agree with Kurt though. jch
On Wed, Feb 24, 2016 at 2:56 PM, Fernando Muñoz <fernando () null-life com> wrote:Hello Eric, I never mentioned privilege escalation. This issue how ever could appear when a different application uses user input and calls "dequote" function that not only dequotes, but also executes it as a command. If mitre doesn't consider it CVE worth, that's OK! Regards. On Wed, Feb 24, 2016 at 3:58 PM, Eric Blake <eblake () redhat com> wrote:On 02/24/2016 12:08 PM, Fernando Muñoz wrote:Marcelo Echeverria and Fernando Muñoz discovered that the dequote function included in bash-completion allows to execute arbitrary commands since it uses the eval function to call printf and perform the actual dequoting. bash-completion is included on Debian, Ubuntu OpenSuse [1] and probably other distros.But what is the privilege escalation? This is no different than incorrectly using 'eval' in a shell script - you may have buggy code, and have an easy-to-trigger bug, but if you can't escalate privileges, how it is a CVE? -- Eric Blake eblake redhat com +1-919-301-3266 Libvirt virtualization library http://libvirt.org
Current thread:
- CVE Request: bash-completion: dequote command injection Fernando Muñoz (Feb 24)
- Re: CVE Request: bash-completion: dequote command injection Eric Blake (Feb 24)
- Re: CVE Request: bash-completion: dequote command injection Fernando Muñoz (Feb 24)
- Re: CVE Request: bash-completion: dequote command injection Kurt Seifried (Feb 24)
- Re: CVE Request: bash-completion: dequote command injection John Haxby (Feb 25)
- Re: CVE Request: bash-completion: dequote command injection Fernando Muñoz (Feb 24)
- Re: CVE Request: bash-completion: dequote command injection Eric Blake (Feb 24)