CVE Intel / CVE-2024-4577

CVE-2024-4577

PHP · fedoraproject, microsoft, php

⚠

Actively exploited in the wild. Listed in the CISA Known Exploited Vulnerabilities catalogue: exploitation confirmed in the wild. Patch on priority.

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This CVE is being exploited. Apply the vendor fix, or take the service off the internet until you can, then check your logs for attempts.

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CISA KEVexploited on our sensorsCritical CVSS 9.8network detectablepublic exploit: ExploitDB, Metasploit

What it is

In PHP versions 8.1.* before 8.1.29, 8.2.* before 8.2.20, 8.3.* before 8.3.8, when using Apache and PHP-CGI on Windows, if the system is set up to use certain code pages, Windows may use "Best-Fit" behavior to replace characters in command line given to Win32 API functions. PHP CGI module may misinterpret those characters as PHP options, which may allow a malicious user to pass options to PHP binary being run, and thus reveal the source code of scripts, run arbitrary PHP code on the server, etc.

Live exploitation on the huntback network (30 days)

attempts captured

distinct source IPs

2026-11-04

last seen

Detection

huntback carries a network signature for this CVE. Exploitation attempts are detected on the decoy fleet in real time.

ExploitDBExploit code published (ExploitDB)

MetasploitExploit code published (Metasploit)

NucleiNuclei detection template available

Evidence

Confirmed exploited. Our decoys saw 4 exploitation attempts in the last 14 days; CISA added it to KEV 883 days ago.

2026-11-04Observed · huntback decoys
Last attempt. 99 attempts on our decoys, 4 in the last 14 days

2026-09-22Observed · huntback decoys
First exploitation attempt on our decoys

2024-06-12Reported · CISA KEV
Added to CISA Known Exploited Vulnerabilities

2024-06-09Context · CVE record
Published

undatedWeaponised · ExploitDB
Exploit code published (ExploitDB)

undatedWeaponised · Metasploit
Exploit code published (Metasploit)

undatedWeaponised · Nuclei
Nuclei detection template available

Observed: our own decoys saw it. Reported: CISA, the vendor or another named source says so. Weaponised: public exploit code or a scanner template exists. Methodology

Questions

Is CVE-2024-4577 being exploited in the wild?

Yes. The huntback decoy network captured 99 exploitation attempts from 29 distinct source IPs; the most recent was on 2026-11-04. It is also in the CISA KEV catalogue.

Can CVE-2024-4577 be detected on the network?

Yes. huntback carries a network signature for CVE-2024-4577, so attempts against a decoy are tagged in real time.

How huntback helps

Deploy a decoy that emulates PHP and you will see every attempt at this CVE the moment it lands, with the full payload, the attacker's infrastructure, and any stage-2 loader. Then huntback can scan the attacker back.

CVSS9.8 Critical

EPSS1.00 (99% pct)

In CISA KEVyes

Published2024-06-09

Updated2026-06-17

Network detectableyes, signatured

Public exploitExploitDB, Metasploit

huntback research

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NVD record → Browse all CVEs → Live malware and C2 finds → Novel-attack discovery → Deploy a decoy →

API

This record, with its evidence timeline, as JSON:

curl -H "X-API-Key: $HUNTBACK_KEY" https://app.huntback.io/api/v1/evidence/CVE-2024-4577

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