-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 I reported the vulnerability below to the Pine team on Oct 21, when 4.20 was current. 4.21 (which I just noticed on freshmeat) seems to fix the problem even though it's not mentioned in the release notes. Since it's not, I thought some disclosure was in order. I built 4.21 in the same way I built 4.20 (below). Best, Jim Hebert <jhebertat_private> - ---------- Forwarded message ---------- Date: Thu, 21 Oct 1999 03:40:27 -0400 (EDT) From: Jim Hebert <jhebertat_private> To: pineat_private Subject: Security: expanding env vars in URLs 1 line summary: environment vars are expanded in URLs I try to view Versions tested: 4.10 and 4.20. 4.10 from "Red Hat" rpm and 4.20 built from pristine sources to slx build target. Both seem equally affected. Discussion: A certain mailing I get occasionally recently had a url like http://something/some/cgi$12345 I noticed viewing the url didn't seem to work right, and finally figured out that the url must get near enough to a shell to allow environment variable expansion. A quick test for me was: echo 'setenv WWW www.securityfocus.com' >> .tcshrc source .tcshrc pine (view a link I mailed myself like: http://$WWW ) it works, I visit securityfocus Doesn't sound dangerous/exploitable yet, right? Well, imagine your shell is bash, someone sends you a html formatted mail, and the url is long: "Click here for cool stuff!" the url is very long, long enough that the dangerous part is elided when pine asks the user to confirm they want to visit that page the url ends with something like: ?trojan=$(shell command) The user says "yeah, sure, visit that page" since they don't see the dangerous part. At the least least, people put your environment variables into their webserver access logs. At most, people can get you to run shell commands (bad enough by itself) _and_ have the output of them sent to them if they wish. I searched the bugtraq archives and didn't see anything about this. Sorry if it's a known issue. Thanks, jim jhebertat_private -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.0.0 (GNU/Linux) Comment: For info see http://www.gnupg.org iD8DBQE4Mzj9B1oRfeAiKDARAs7ZAJ9WpvdZ8aVLAl1N89dXl1mun1jFLQCeP8lq 2F6L+3uiYG63eOpgVv0ME5I= =Zj4l -----END PGP SIGNATURE-----
This archive was generated by hypermail 2b30 : Fri Apr 13 2001 - 15:13:15 PDT