From: Simon McVittie Date: Sat, 24 Dec 2016 15:03:51 +0000 (+0000) Subject: Force CGI::FormBuilder->field to scalar context where necessary X-Git-Tag: debian/3.20141016.4~38 X-Git-Url: http://git.vanrenterghem.biz/git.ikiwiki.info.git/commitdiff_plain/446fc9e6ab06c7743b8f659de829f166b1778991 Force CGI::FormBuilder->field to scalar context where necessary CGI::FormBuilder->field has behaviour similar to the CGI.pm misfeature we avoided in f4ec7b0. Force it into scalar context where it is used in an argument list. This prevents two (relatively minor) commit metadata forgery vulnerabilities: * In the comments plugin, an attacker who was able to post a comment could give it a user-specified author and author-URL even if the wiki configuration did not allow for that, by crafting multiple values to other fields. * In the editpage plugin, an attacker who was able to edit a page could potentially forge commit authorship by crafting multiple values for the rcsinfo field. The remaining plugins changed in this commit appear to have been protected by use of explicit scalar prototypes for the called functions, but have been changed anyway to make them more obviously correct. In particular, checkpassword() in passwordauth has a known prototype, so an attacker cannot trick it into treating multiple values of the name field as being the username, password and field to check for. OVE-20161226-0001 (cherry picked from commit c1120bbbe8fdea20cf64fa12247f4f4a4006c834) --- diff --git a/IkiWiki/Plugin/attachment.pm b/IkiWiki/Plugin/attachment.pm index 9bac96fc6..04100e0fd 100644 --- a/IkiWiki/Plugin/attachment.pm +++ b/IkiWiki/Plugin/attachment.pm @@ -163,7 +163,7 @@ sub formbuilder (@) { # Generate the attachment list only after having added any new # attachments. - $form->tmpl_param("attachment_list" => [attachment_list($form->field('page'))]); + $form->tmpl_param("attachment_list" => [attachment_list(scalar $form->field('page'))]); } sub attachment_holding_location { diff --git a/IkiWiki/Plugin/comments.pm b/IkiWiki/Plugin/comments.pm index c5177833f..aa9b49c8c 100644 --- a/IkiWiki/Plugin/comments.pm +++ b/IkiWiki/Plugin/comments.pm @@ -555,11 +555,12 @@ sub editcomment ($$) { } $postcomment=1; - my $ok=IkiWiki::check_content(content => $form->field('editcontent'), - subject => $form->field('subject'), + my $ok=IkiWiki::check_content( + content => scalar $form->field('editcontent'), + subject => scalar $form->field('subject'), $config{comments_allowauthor} ? ( - author => $form->field('author'), - url => $form->field('url'), + author => scalar $form->field('author'), + url => scalar $form->field('url'), ) : (), page => $location, cgi => $cgi, @@ -599,7 +600,7 @@ sub editcomment ($$) { length $form->field('subject')) { $message = sprintf( gettext("Added a comment: %s"), - $form->field('subject')); + scalar $form->field('subject')); } IkiWiki::rcs_add($file); diff --git a/IkiWiki/Plugin/editpage.pm b/IkiWiki/Plugin/editpage.pm index 78d0704c7..fad7ecc5a 100644 --- a/IkiWiki/Plugin/editpage.pm +++ b/IkiWiki/Plugin/editpage.pm @@ -430,7 +430,7 @@ sub cgi_editpage ($$) { $conflict=rcs_commit( file => $file, message => $message, - token => $form->field("rcsinfo"), + token => scalar $form->field("rcsinfo"), session => $session, ); enable_commit_hook(); diff --git a/IkiWiki/Plugin/notifyemail.pm b/IkiWiki/Plugin/notifyemail.pm index b50a22a00..079bb10d4 100644 --- a/IkiWiki/Plugin/notifyemail.pm +++ b/IkiWiki/Plugin/notifyemail.pm @@ -34,7 +34,7 @@ sub formbuilder (@) { } elsif ($form->submitted eq "Save Preferences" && $form->validate && defined $form->field("subscriptions")) { - setsubscriptions($username, $form->field('subscriptions')); + setsubscriptions($username, scalar $form->field('subscriptions')); } } diff --git a/IkiWiki/Plugin/passwordauth.pm b/IkiWiki/Plugin/passwordauth.pm index 346515e23..fe1da764a 100644 --- a/IkiWiki/Plugin/passwordauth.pm +++ b/IkiWiki/Plugin/passwordauth.pm @@ -231,7 +231,7 @@ sub formbuilder_setup (@) { $form->field( name => "password", validate => sub { - checkpassword($form->field("name"), shift); + checkpassword(scalar $form->field("name"), shift); }, ); } @@ -390,7 +390,7 @@ sub formbuilder (@) { if ($form->submitted eq "Save Preferences" && $form->validate) { my $user_name=$form->field('name'); if (defined $form->field("password") && length $form->field("password")) { - setpassword($user_name, $form->field('password')); + setpassword($user_name, scalar $form->field('password')); } } } diff --git a/IkiWiki/Plugin/po.pm b/IkiWiki/Plugin/po.pm index 6107a4a22..1528f235f 100644 --- a/IkiWiki/Plugin/po.pm +++ b/IkiWiki/Plugin/po.pm @@ -548,7 +548,7 @@ sub formbuilder_setup (@) { # their buttons, which is why this hook must be run last. # The canrename/canremove hooks already ensure this is forbidden # at the backend level, so this is only UI sugar. - if (istranslation($form->field("page"))) { + if (istranslation(scalar $form->field("page"))) { map { for (my $i = 0; $i < @{$params{buttons}}; $i++) { if (@{$params{buttons}}[$i] eq $_) { diff --git a/IkiWiki/Plugin/rename.pm b/IkiWiki/Plugin/rename.pm index 6d56340b8..2456c22cb 100644 --- a/IkiWiki/Plugin/rename.pm +++ b/IkiWiki/Plugin/rename.pm @@ -258,7 +258,7 @@ sub formbuilder (@) { my $session=$params{session}; if ($form->submitted eq "Rename" && $form->field("do") eq "edit") { - rename_start($q, $session, 0, $form->field("page")); + rename_start($q, $session, 0, scalar $form->field("page")); } elsif ($form->submitted eq "Rename Attachment") { my @selected=map { Encode::decode_utf8($_) } $q->param("attachment_select"); @@ -311,7 +311,7 @@ sub sessioncgi ($$) { # performed in check_canrename later. my $srcfile=IkiWiki::possibly_foolish_untaint($pagesources{$src}) if exists $pagesources{$src}; - my $dest=IkiWiki::possibly_foolish_untaint(titlepage($form->field("new_name"))); + my $dest=IkiWiki::possibly_foolish_untaint(titlepage(scalar $form->field("new_name"))); my $destfile=$dest; if (! $q->param("attachment")) { my $type=$q->param('type');