Index: openacs-4/packages/acs-tcl/tcl/security-procs.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/acs-tcl/tcl/security-procs.tcl,v
diff -u -r1.126.2.62 -r1.126.2.63
--- openacs-4/packages/acs-tcl/tcl/security-procs.tcl	7 Feb 2022 12:21:39 -0000	1.126.2.62
+++ openacs-4/packages/acs-tcl/tcl/security-procs.tcl	16 Mar 2022 13:18:07 -0000	1.126.2.63
@@ -1371,6 +1371,10 @@
     @param secret specifies an external secret to use instead of the
     one provided by the ACS signature mechanism.
 } {
+    if {![string is list $signature]} {
+        ns_log warning "signature is not a list '$signature'"
+        return 0
+    }
     lassign $signature token_id expire_time hash
     return [__ad_verify_signature $value $token_id $secret $expire_time $hash]
 }
@@ -1386,6 +1390,10 @@
     @param secret specifies an external secret to use instead of the
     one provided by the ACS signature mechanism.
 } {
+    if {![string is list $signature]} {
+        ns_log warning "signature is not a list '$signature'"
+        return 0
+    }
     lassign $signature token_id expire_time hash
     if { [__ad_verify_signature $value $token_id $secret $expire_time $hash] } {
         return $expire_time