This information is originally from http://www.ijs.si/software/amavisd/
(Thanks to amavisd-new, Mark Martinec, and Vivek Khera!)

If SpamAssassin is running in taint-mode (the default) and is configured to
call Vipul's Razor 2.22 or higher, then Razor2 checks will fail because the
Razor2 code is not quite taint-safe.  The problem is still present in 2.36
and the SpamAssassin developers do not know when or how this will be
addressed so please don't ask us!

To apply: cd to the directory /usr/{lib,share}/perl5/.../Razor2 (wherever
the Client subdirectory is located) and apply the patch directly with:

  patch -p0 < Razor2.patch

or apply to the Razor2 source tree with:

  patch -p0 -d lib/Razor2 < Razor2.patch

Please make sure that no unpatched copies of Razor are installed on your
system.  Sometimes, there is more than one installed copy.

--- Client/Agent.pm~	Tue Nov 19 16:26:05 2002
+++ Client/Agent.pm	Sun Sep 21 23:20:47 2003
@@ -969,6 +969,7 @@
     my @fns;
     if (opendir D,$self->{razorhome}) {
         @fns = map "$self->{razorhome}/$_", grep /^server\.[\S]+\.conf$/, readdir D;
+        @fns = map { /^(\S+)$/, $1 } @fns; # untaint
         closedir D;
     }
     foreach (@fns) {
--- Client/Config.pm~	Thu Nov 14 14:47:01 2002
+++ Client/Config.pm	Sun Sep 21 23:18:52 2003
@@ -323,9 +323,11 @@
         if ($fn =~ /^(.*)\/([^\/]+)$/) {
             my $dir = $1;
             $fn = readlink $fn;
+            $fn = $1 if $fn =~ /^(\S+)$/; # untaint readlink
             $fn = "$dir/$fn" unless $fn =~ /^\//;
         } else {
             $fn = readlink $fn;
+            $fn = $1 if $fn =~ /^(\S+)$/; # untaint readlink
         }
     }
 }
@@ -366,13 +368,13 @@
         chomp; 
         next if /^\s*#/;
         if ($nothash) {
-            s/^\s+//; s/\s+$//;
+            next unless s/^\s*(.+?)\s*$/$1/; # untaint
             $conf->{$_} = 7;
             push @lines, $_;
         } else { 
             next unless /=/;
-            my ($attribute, $value) = split /\=/, $_, 2; 
-            $attribute =~ s/^\s+//; $attribute =~ s/\s+$//;
+            my ($attribute, $value) = /^\s*(.+?)\s*=\s*(.+?)\s*$/; # untaint
+            next unless (defined $attribute && defined $value);
             $conf->{$attribute} = $self->parse_value($value);
         }
         $total++;
--- Client/Core.pm~	Wed Nov 13 12:01:10 2002
+++ Client/Core.pm	Sun Sep 21 23:20:21 2003
@@ -216,8 +216,10 @@
         foreach $rr ($query->answer) { 
             my $pushed = 0;
             if ($rr->type eq "A") { 
-                push @list, $rr->address; 
-                $pushed = 1;
+                if ($rr->address =~ m/^(\d+\.\d+\.\d+\.\d+)$/) {
+                    push @list, $1; 
+                    $pushed = 1;
+                }
             } elsif ($rr->type eq "CNAME") { 
                 if ($rr->cname eq 'list.terminator') { 
                     pop @list if $pushed;