This indicates an attack attempt to exploit a Privilege Escalation vulnerability in Apache.
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 escalate their privileges on vulnerable systems.
Apache 2.4.38, 2.4.37, 2.4.35, 2.4.34, 2.4.33, 2.4.30, 2.4.29, 2.4.28, 2.4.27, 2.4.26, 2.4.25, 2.4.23, 2.4.20, 2.4.18, 2.4.17
Privilege Escalation: Remote attackers can leverage their privileges on vulnerable systems.
Apply the most recent upgrade or patch from the vendor.