oss-sec mailing list archives
Re: Remote file inclusion by office applications
From: Daniel Kahn Gillmor <dkg () fifthhorseman net>
Date: Thu, 13 Dec 2012 13:53:49 -0500
On 12/13/2012 11:44 AM, Kurt Seifried wrote:
I'm kind of leaning towards classifying this as a security issue since I expected there is some way to disable it or at least tell it to prompt me when a document tries to go get an external data source (e.g. "this document contains external data, the URLs/file paths it is trying to reference are: [list of locations]") but apparently there is no way to disable/have this prompt (at least that I can find in LibreOffice)?
I think your assessment is correct. I've just now made an ODT file that libreoffice uses to not only hit the network for a PNG (denial of service attacks, remote exploitation of other flaws in libpng or in LO itself, virus scanner bypass, etc), but one that will include and render ~/.ssh/id_rsa as a text/plain document. This seems like it could be done against any local privileged file. For local file inclusion, libreoffice at leasts prompts me with: ----------- This document contains one or more links to external data. Would you like to change the document, and update all links to get the most recent data? [Yes] [No] ----------- but it doesn't tell me what those documents are. And given the UI history of people clicking through popups they don't understand, i'm not convinced that this popup is going to do anything to prevent remote disclosure (it even defaults to "Yes"). When i say "no" on the prompt, it goes out and fetches networked URLs anyway, so i assume this prompt is supposed to just refer to local "external data". --dkg
Current thread:
- Remote file inclusion by office applications Timo Warns (Dec 13)
- Re: Remote file inclusion by office applications Kurt Seifried (Dec 13)
- Re: Remote file inclusion by office applications Timo Warns (Dec 13)
- Re: Remote file inclusion by office applications Daniel Kahn Gillmor (Dec 13)
- Re: Remote file inclusion by office applications Kurt Seifried (Dec 13)
- Re: Remote file inclusion by office applications Tim Brown (Dec 13)
- Re: Remote file inclusion by office applications Florian Weimer (Dec 14)
- Re: Remote file inclusion by office applications Kurt Seifried (Dec 13)