This indicates an attack attempt to exploit an Out Of Bounds Write vulnerability in PHP.
The vulnerability is due to an error when the vulnerable software handles a maliciously crafted file. A remote attacker may be able to exploit this to execute arbitrary code on vulnerable systems.
PHP 5.x before 5.6.40
PHP 7.1.x before 7.1.26, 7.2.x before 7.2.14, and 7.3.x before 7.3.1
System Compromise: Remote attackers can gain control of vulnerable systems.
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