diff -uNr squid-4.8/src/esi/VarState.cc squid-4.8.mod/src/esi/VarState.cc
--- squid-4.8/src/esi/VarState.cc	2019-07-09 22:05:20.000000000 +0300
+++ squid-4.8.mod/src/esi/VarState.cc	2019-09-23 17:31:10.292888618 +0300
@@ -150,7 +150,7 @@
 {
     char const *t;
     int len;
-    t = index(s,'/');
+    t = strchr(s,'/');
 
     if (!t || !*(++t))
         return xstrdup("");
@@ -328,12 +328,12 @@
 
         if ((t = strstr (s, "MSIE"))) {
             browser = ESI_BROWSER_MSIE;
-            t = index (t, ' ');
+            t = strchr (t, ' ');
 
             if (!t)
                 browserversion = xstrdup("");
             else {
-                t1 = index(t, ';');
+                t1 = strchr(t, ';');
 
                 if (!t1)
                     browserversion = xstrdup(t + 1);
