Apache HTTP Server up to 2.4.63 on Windows mod_rewrite server-side request forgery

Summaryinfo

A vulnerability was found in Apache HTTP Server up to 2.4.63 on Windows. It has been rated as critical. The impacted element is an unknown function of the component mod_rewrite. This manipulation causes server-side request forgery. This vulnerability is registered as CVE-2024-43394. Remote exploitation of the attack is possible. No exploit is available. Upgrading the affected component is advised.

Detailsinfo

A vulnerability was found in Apache HTTP Server up to 2.4.63 on Windows. It has been declared as critical. Affected by this vulnerability is an unknown function of the component mod_rewrite. The manipulation with an unknown input leads to a server-side request forgery vulnerability. The CWE definition for the vulnerability is CWE-918. The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

Server-Side Request Forgery (SSRF) in Apache HTTP Server on Windows allows to potentially leak NTLM hashes to a malicious server via  mod_rewrite or apache expressions that pass unvalidated request input. This issue affects Apache HTTP Server: from 2.4.0 through 2.4.63. Note:  The Apache HTTP Server Project will be setting a higher bar for accepting vulnerability reports regarding SSRF via UNC paths. The server offers limited protection against administrators directing the server to open UNC paths. Windows servers should limit the hosts they will connect over via SMB based on the nature of NTLM authentication.

The weakness was published by Kainan Zhang. It is possible to read the advisory at httpd.apache.org. This vulnerability is known as CVE-2024-43394 since 08/12/2024. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. The technical details are unknown and an exploit is not publicly available. The pricing for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 08/15/2025).

The vulnerability scanner Nessus provides a plugin with the ID 241984 (Apache 2.4.x < 2.4.64 Multiple Vulnerabilities), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 2.4.64 eliminates this vulnerability.

The vulnerability is also documented in the databases at Tenable (241984), EUVD (EUVD-2024-54772) and CERT Bund (WID-SEC-2025-1850). Be aware that VulDB is the high quality source for vulnerability data.

Affected

• Xerox FreeFlow Print Server

Productinfo

Type

• Web Server

Vendor

• Apache

Name

• HTTP Server

Version

• 2.4.0
• 2.4.1
• 2.4.2
• 2.4.3
• 2.4.4
• 2.4.5
• 2.4.6
• 2.4.7
• 2.4.8
• 2.4.9
• 2.4.10
• 2.4.11
• 2.4.12
• 2.4.13
• 2.4.14
• 2.4.15
• 2.4.16
• 2.4.17
• 2.4.18
• 2.4.19
• 2.4.20
• 2.4.21
• 2.4.22
• 2.4.23
• 2.4.24
• 2.4.25
• 2.4.26
• 2.4.27
• 2.4.28
• 2.4.29
• 2.4.30
• 2.4.31
• 2.4.32
• 2.4.33
• 2.4.34
• 2.4.35
• 2.4.36
• 2.4.37
• 2.4.38
• 2.4.39
• 2.4.40
• 2.4.41
• 2.4.42
• 2.4.43
• 2.4.44
• 2.4.45
• 2.4.46
• 2.4.47
• 2.4.48
• 2.4.49
• 2.4.50
• 2.4.51
• 2.4.52
• 2.4.53
• 2.4.54
• 2.4.55
• 2.4.56
• 2.4.57
• 2.4.58
• 2.4.59
• 2.4.60
• 2.4.61
• 2.4.62
• 2.4.63

License

• open-source

Website

• Vendor: https://www.apache.org/

CPE 2.3info

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CPE 2.2info

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CVSSv4info

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Exploitinginfo

Threat Intelligenceinfo

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Entryinfo

Be aware that VulDB is the high quality source for vulnerability data.

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