CVE-2024-4577

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.

CVSS: 9.8Criticalscored by the publisher (CNA)
Exploited in the wild: Yes, in CISA KEV since 12 Jun 2024CISA deadline for US federal agencies: 3 Jul 2024known use in ransomware campaignspublic exploit code
EPSS: > 99.9%chance of exploitation in the next 30 daystop 0.1% of scored CVEsFIRST score of 11 Nov 2026
Fix: Fixed in 8.1.29, 8.2.20, 8.3.8per the vendor
Published: 9 Jun 2024analysed here 12 Nov 2026

Do first. Upgrade to a fixed release: 8.1.29, 8.2.20, 8.3.8.

Summary

Triage

Attack surface: Server-side
Exploitable: At runtime
Attack vector: network
Weakness: CWE-78 OS Command Injection

The summary, impact and action text on this page are written by our AI analysis pipeline, or taken from the NVD description when a CVE was imported from NVD. They are not the vendor's wording: check them against the sources. A longer AI executive summary and technical analysis are generated for signed-in accounts on the Max plan.

Affected products

Product	Affected versions	Vendor says fixed in
libphpfrom the Bitnami advisory, via OSV	< 8.1.29>= 8.2.0 and < 8.2.20>= 8.3.0 and < 8.3.8Vendor says fixed in: 8.1.29, 8.2.20, 8.3.8	8.1.298.2.208.3.8
PHPfrom the Bitnami advisory, via OSV	< 8.1.29>= 8.2.0 and < 8.2.20>= 8.3.0 and < 8.3.8Vendor says fixed in: 8.1.29, 8.2.20, 8.3.8	8.1.298.2.208.3.8
PHP Group PHP	>= 8.1.* and < 8.1.29>= 8.2.* and < 8.2.20>= 8.3.* and < 8.3.8Vendor says fixed in: not stated	Not stated by the vendor

As published in the CVE Program record, and, for products that ship the affected component, in the advisory named beside them. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.

Products named in our analysis

php:php
fedoraproject:fedora

Fix and mitigation

WAF and other mitigations

Can a WAF block it? Partly. OS command injection puts shell syntax into the request. WAF rules catch common shell commands but miss encoded or unusual payloads.

Also consider: shlex/execve-style APIs

Based on the weakness type only; no CVE-specific evidence yet. We check Cloudflare, AWS, Google Cloud Armor and Azure; for Akamai, Imperva, Fastly, F5, ask your vendor.

Remediation steps (AI-written)

Step-by-step remediation is generated for accounts on the Max plan, for CVEs that match a technology in their stack. Add this technology to your stack to see the fix checklist.

Exploitation evidence

CISA KEV catalog: Listed since 12 Jun 2024. Known use in ransomware campaigns.
CISA due date: 3 Jul 2024, the remediation deadline for US federal agencies
CISA required action: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
Public exploit code: Yes: 1 on Exploit-DB · 1 Metasploit module · 73 GitHub proofs of concept · 1 Nuclei template
CISA SSVC: exploitation active, automatable yes, technical impact totalAssessed by CISA 15 Jun 2024 (SSVC 2.0.3). Exploitation is none, poc (public proof of concept) or active.

and 69 more repositories

Listed so you can judge urgency, not as a recommendation to run anything. GitHub “proofs of concept” are unvetted: some are fake or carry malware. Exploit-DB marks the entries its staff verified.

Timeline

7 Jun 2024First public exploit or proof of concept
9 Jun 2024Published3 days later
12 Jun 2024Added to CISA KEV (exploited in the wild)2 days later
15 Jun 2024CISA SSVC assessment: exploitation active3 days later
3 Jul 2024CISA remediation due date (US federal agencies)18 days later
21 Oct 2025CVE record last updated476 days (about 1 year) later
12 Nov 2026Analysed by vulneraibility.com387 days (about 1 year) later

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Metric	Value	What it means
Attack vector	NetworkReachable over the internet or any routable network.	Reachable over the internet or any routable network.
Attack complexity	LowRepeatable attack, no special conditions.	Repeatable attack, no special conditions.
Privileges required	NoneThe attacker needs no prior access.	The attacker needs no prior access.
User interaction	NoneNo victim action needed.	No victim action needed.
Scope	UnchangedImpact stays within the vulnerable component.	Impact stays within the vulnerable component.
Confidentiality	HighTotal data disclosure possible.	Total data disclosure possible.
Integrity	HighComplete modification possible.	Complete modification possible.
Availability	HighFull outage possible.	Full outage possible.

Common questions

Is CVE-2024-4577 being exploited?

Yes. CVE-2024-4577 appears in CISA's Known Exploited Vulnerabilities catalog, which means exploitation in the wild has been confirmed and reported. Treat it as active rather than theoretical, and patch it ahead of higher-scoring vulnerabilities that carry no exploitation evidence.

How severe is CVE-2024-4577?

CVE-2024-4577 is rated Critical with a CVSS score of 9.8. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.

Is there a patch for CVE-2024-4577?

Yes. A fix has been recorded for CVE-2024-4577. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.

What does CVE-2024-4577 affect?

CVE-2024-4577 affects php:php, fedoraproject:fedora. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.

Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.

References

NVD CVE.org CVE Details Source

23 references in the CVE record, grouped by the tags the record gives them.

Where the data on this page comes from

CVE List (CVE.org): description, affected versions, references; CVE Terms of Use
NVD: CVSS and CPE data
CISA KEV catalog: exploitation, date added, due date
CISA Vulnrichment (ADP): SSVC decision points
FIRST EPSS: exploit probability and percentile
Exploit-DB: published exploits
Metasploit Framework: exploit and scanner modules
Nuclei templates: detection templates
PoC-in-GitHub: GitHub repositories that claim a proof of concept
OSV: advisory aliases and downstream package versions

Summary, impact and triage tags: written by our AI analysis pipeline from the sources above. Check them against the sources.

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