From: Joey Hess <joey@kitenet.net>
Date: Sat, 5 Jan 2008 06:01:11 +0000 (-0500)
Subject: web commit by adb
X-Git-Url: https://sipb.mit.edu/gitweb.cgi/ikiwiki.git/commitdiff_plain/f9fa96ded77418851da8b094f73c25dbde8a9714?ds=inline

web commit by adb
---

diff --git a/doc/bugs/taint_issue_with_regular_expressions.mdwn b/doc/bugs/taint_issue_with_regular_expressions.mdwn
new file mode 100644
index 000000000..174b4f1c5
--- /dev/null
+++ b/doc/bugs/taint_issue_with_regular_expressions.mdwn
@@ -0,0 +1,9 @@
+Built from 2.1.17 source, works fine on commandline, but not working from CGI wrapper.  Traced problem to regular expressions failing to match, specifically in contexts like the following in Render.pm:
+
+    my ($f)=/$config{wiki_file_regexp}/; # untaint
+
+It works if I replace it with:
+
+    my ($f)=/(^[-[:alnum:]_.:\/+]+$)/; # untaint
+
+which is exactly the same regular expression drawn out as a constant.  It appears that %config gets some tainted data and is itself being marked entirely tainted, which may prevent using regular expressions contained in it for untainting other data.  I'm using Perl 5.8.8.