sfewer-r7's assessment of CVE-2024-4577

Description

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.

Add Assessment

sfewer-r7 (129)

June 10, 2024 5:00pm UTC (6 months ago)•

Ratings

Attacker Value

High

Exploitability

Low

Easy to weaponize Unauthenticated Vulnerable in uncommon configuration

Technical Analysis

I have rated the attacker value as high, as if the requirement to exploitation are met the attacker can get remote unauthenticated RCE on the target Windows server. I have rated the Exploitability as Low as there are several prerequisites for a target to be vulnerable, specifically.

Target must be a web server running on a Windows system. A Web server on Linux for example can not be vulnerable. Currently I have only seen vulnerable Apache based configurations. I could not get IIS to be vulnerable during testing.
Target webserver must expose PHP in CGI mode (as opposed to FastCGI mode which is generally more common), or expose the CGI binary directly through an Apache ScriptAlias directive.
The target Windows OS must have its system locale set to either Japanese (Code page 932) or Chinese (Code pages 950 or 936). For this reason most systems that meet the other requirements will not be exploitable, as the systems locale must use a code page that can cause the vulnerability.

It is worth noting that XAMPP for Windows is in a vulnerable configuration by default, however the target Windows system XAMPP is running on still must meet the locale requirement of either Japanese or Chinese as mentioned above.

CVSS V3 Severity and Metrics

Data provided by the National Vulnerability Database (NVD)

Base Score:

9.8 Critical

Impact Score:

5.9

Exploitability Score:

3.9

Vector:

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

Attack Vector (AV):

Network

Attack Complexity (AC):

Low

Privileges Required (PR):

None

User Interaction (UI):

None

Scope (S):

Unchanged

Confidentiality (C):

High

Integrity (I):

High

Availability (A):

High

Vendors

fedoraproject,
php

Products

fedora 39,
fedora 40,
php

Metasploit Modules

exploit/windows/http/php_cgi_arg_injection_rce_cve_2024_4577 (https://github.com/rapid7/metasploit-framework/blob/master/modules/exploits/windows/http/php_cgi_arg_injection_rce_cve_2024_4577.rb)

Exploited in the Wild

Reported by:

inokii indicated sources as

Government or Industry Alert (https://www.cisa.gov/known-exploited-vulnerabilities-catalog)
Other: CISA Gov Alert (https://www.cisa.gov/news-events/alerts/2024/06/12/cisa-adds-two-known-exploited-vulnerabilities-catalog)

Reported: June 14, 2024 2:01pm UTC (6 months ago)

AttackerKB Worker indicated source as Government or Industry Alert (https://www.cisa.gov/news-events/alerts/2024/06/12/cisa-adds-two-known-exploited-vulnerabilities-catalog)

Reported: November 08, 2024 8:27am UTC (1 month ago)

References

Canonical

CVE-2024-4577 (https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2024-4577)

Exploit

PoCs that have not been added by contributors directly have been sourced from: nomi-sec/PoC-in-GitHub.
A PoC added here by the AKB Worker must have at least 2 GitHub stars.

CVE-2024-4577 (https://github.com/ATDanny/CVE-2024-4577) (Added by AKB Worker)

CVE-2024-4577 (https://github.com/manuelinfosec/CVE-2024-4577) (Added by AKB Worker)

CVE-2024-4577-PHP-RCE (https://github.com/xcanwin/CVE-2024-4577-PHP-RCE) (Added by AKB Worker)

CVE-2024-4577-PoC (https://github.com/ZephrFish/CVE-2024-4577-PoC) (Added by AKB Worker)

CVE-2024-4577-nuclei (https://github.com/0x20c/CVE-2024-4577-nuclei) (Added by AKB Worker)

CVE-2024-4577 (https://github.com/Chocapikk/CVE-2024-4577) (Added by AKB Worker)

CVE-2024-4577 (https://github.com/Sh0ckFR/CVE-2024-4577) (Added by AKB Worker)

CVE-2024-4577 (https://github.com/gotr00t0day/CVE-2024-4577) (Added by AKB Worker)

CVE-2024-4577 (https://github.com/sug4r-wr41th/CVE-2024-4577) (Added by AKB Worker)

CVE-2024-4577 (https://github.com/VictorShem/CVE-2024-4577) (Added by AKB Worker)

CVE-2024-4577 (https://github.com/zomasec/CVE-2024-4577) (Added by AKB Worker)

CVE-2024-4577-RCE (https://github.com/l0n3m4n/CVE-2024-4577-RCE) (Added by AKB Worker)