For an exploit writer, CVE-2022-31625 is a goldmine—an info leak that complements a separate RCE bug.
Because PHP 7.4 reached its official community end-of-life (EOL) in late 2022, systems still running Zend Engine v3.4.0 are highly susceptible to known exploits unless they use extended commercial support . Key Exploits and Vulnerabilities zend engine v3.4.0 exploit
If you are looking at a specific system reporting "Zend Engine v3.4.0", it is almost certainly one of the following PHP 7.4 releases: For an exploit writer, CVE-2022-31625 is a goldmine—an
typedef union _zend_value zend_long lval; // long integer double dval; // double zend_refcounted *counted; // strings, arrays, objects zend_string *str; zend_array *arr; zend_object *obj; // ... zend_value; zend_value; Disclaimer: This article is for educational and
Disclaimer: This article is for educational and defensive security research purposes only. Exploiting systems without explicit authorization is illegal and unethical.
Historically, Zend Engine 3.x suffered from a subtle UAF in the garbage collector for cyclic arrays. An attacker could create a circular reference, trigger gc_collect_cycles() , and then, using a second PHP reference, access the freed memory.
With type confusion, the attacker can pivot to an . For example, if a zend_string 's length field can be overwritten with a large value, subsequent $leaked = $fake_string[0x1337] will read out-of-bounds heap data, revealing function pointers (breaking ASLR) or heap metadata.