From 885444fcbe10dc42787ecb76686c8ee4dd33bf33 Mon Sep 17 00:00:00 2001
From: Ken Sharp <ken.sharp@artifex.com>
Date: Tue, 20 Aug 2019 10:10:28 +0100
Subject: make .forceput inaccessible
Bug #701343, #701344, #701345
More defensive programming. We don't want people to access .forecput
even though it is no longer sufficient to bypass SAFER. The exploit
in #701343 didn't work anyway because of earlier work to stop the error
handler being used, but nevertheless, prevent access to .forceput from
.setuserparams2.
diff --git a/Resource/Init/gs_lev2.ps b/Resource/Init/gs_lev2.ps
index 4cc7f820f..0fd416465 100644
--- a/Resource/Init/gs_lev2.ps
+++ b/Resource/Init/gs_lev2.ps
@@ -158,7 +158,7 @@ end
{
pop pop
} ifelse
- } forall
+ } executeonly forall
% A context switch might have occurred during the above loop,
% causing the interpreter-level parameters to be reset.
% Set them again to the new values. From here on, we are safe,
@@ -229,9 +229,9 @@ end
{ pop pop
}
ifelse
- }
+ } executeonly
forall pop
-} .bind odef
+} .bind executeonly odef
% Initialize the passwords.
% NOTE: the names StartJobPassword and SystemParamsPassword are known to
diff --git a/Resource/Init/gs_pdfwr.ps b/Resource/Init/gs_pdfwr.ps
index c158a8faf..422e66e1a 100644
--- a/Resource/Init/gs_pdfwr.ps
+++ b/Resource/Init/gs_pdfwr.ps
@@ -658,11 +658,11 @@ currentdict /.pdfmarkparams .undef
systemdict /.pdf_hooked_DSC_Creator //true .forceput
} executeonly if
pop
- } if
+ } executeonly if
} {
pop
} ifelse
- }
+ } executeonly
{
pop
} ifelse