CVE-2024-43204
Description
A Server-side request forgery (SSRF) vulnerability exists in Apache httpd when the server has mod_proxy loaded and is configured with mod_headers to modify the Content-Type header in the HTTP request or response using a value supplied by the user. Under this configuration, this flaw allows an attacker to craft specially crafted requests to manipulate the Content-Type header and trigger outbound requests to arbitrary attacker-controlled URLs via proxy. The vulnerability stems from inadequate input validation and unsafe header manipulation, ultimately allowing an attacker to influence server-side network behavior.
Statement
Exploitation requires a non-default and uncommon server configuration where mod_headers is configured to modify the Content-Type request or a response header with a value provided in the HTTP request.
This issue is rated as a Moderate vulnerability primarily due to its reliance on a non-default and uncommon server configuration, which significantly limits its exploitability. Specifically, successful exploitation requires the Apache HTTP Server to have both mod_proxy and mod_headers enabled, and for mod_headers to be explicitly misconfigured to set or modify the Content-Type header using unvalidated user input—a rare and generally discouraged setup. Moreover, the SSRF does not result in information disclosure, privilege escalation, or code execution, but merely allows outbound connections from the server to attacker-controlled endpoints.
Mitigation
No mitigation is currently available that meets Red Hat Product Security’s standards for usability, deployment, applicability, or stability.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 5.4 | N/A | 7.5 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | High | N/A | Low |
| Privileges Required | None | N/A | None |
| User Interaction | None | N/A | None |
| Scope | Changed | N/A | Unchanged |
| Confidentiality | Low | N/A | None |
| Integrity Impact | Low | N/A | High |
| Availability Impact | None | N/A | None |
Vector
Red Hat: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
Understanding the Weakness (CWE)
Confidentiality
Technical Impact: Read Application Data
Integrity
Technical Impact: Execute Unauthorized Code or Commands
Access Control
Technical Impact: Bypass Protection Mechanism
By providing URLs to unexpected hosts or ports, attackers can make it appear that the server is sending the request, possibly bypassing access controls such as firewalls that prevent the attackers from accessing the URLs directly. The server can be used as a proxy to conduct port scanning of hosts in internal networks, use other URLs such as that can access documents on the system (using file://), or use other protocols such as gopher:// or tftp://, which may provide greater control over the contents of requests.
Frequently Asked Questions
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