Overview
CVE-2025-13434 describes a medium severity vulnerability found in the jameschz Hush Framework version 2.0. Specifically, the vulnerability is an HTTP Host Header Injection issue located within the Hush\hush-lib\hush\Util.php file. The vulnerability stems from improper neutralization of HTTP headers when handling scripting syntax within the $_SERVER['HOST'] argument. Successful exploitation allows for remote attackers to potentially inject malicious code or manipulate application behavior.
Importantly, this vulnerability is publicly known, and an exploit is available. The vendor was contacted but did not respond to the disclosure.
Technical Details
The core of the vulnerability lies in how the Hush Framework processes the HTTP Host header. The Util.php file’s affected function does not adequately sanitize the $_SERVER['HOST'] value. This lack of proper input validation allows an attacker to inject arbitrary code or scripting syntax within the HTTP Host header. This injected code can then be executed by the application, leading to various security issues.
The manipulation allows for HTTP header injection, which can lead to Cross-Site Scripting (XSS) attacks, cache poisoning, or other malicious activities depending on how the application utilizes the unsanitized Host header.
CVSS Analysis
The vulnerability has been assigned a CVSS score of 5.3, indicating a MEDIUM severity. This score reflects the following factors:
- Attack Vector (AV): Network (N) – The attack can be performed remotely.
- Attack Complexity (AC): Low (L) – The attack is relatively easy to execute.
- Privileges Required (PR): None (N) – No privileges are required to exploit the vulnerability.
- User Interaction (UI): None (N) – No user interaction is required for exploitation.
- Scope (S): Unchanged (U) – An exploited vulnerability can only affect resources managed by the same security authority.
- Confidentiality Impact (C): None (N) – There is no impact to confidentiality.
- Integrity Impact (I): Low (L) – There is a limited impact to integrity.
- Availability Impact (A): None (N) – There is no impact to availability.
While the CVSS score is medium, the fact that an exploit is publicly available increases the risk associated with this vulnerability.
Possible Impact
Successful exploitation of CVE-2025-13434 can lead to several potential impacts:
- Cross-Site Scripting (XSS): An attacker can inject malicious scripts into the application’s pages, allowing them to steal user credentials, redirect users to malicious websites, or deface the website.
- Cache Poisoning: An attacker can manipulate the Host header to poison the application’s cache, serving malicious content to other users.
- Account Takeover: In certain scenarios, the attacker may use this vulnerability to take over user accounts.
- Information Disclosure: Depending on how the application uses the Host header, an attacker may be able to obtain sensitive information.
Mitigation or Patch Steps
Unfortunately, since the vendor has not responded, there is no official patch available. Therefore, mitigation strategies are necessary:
- Input Validation and Sanitization: Implement strict input validation and sanitization for the
$_SERVER['HOST']variable. Ensure that all potentially malicious characters are properly escaped or removed. Use whitelisting techniques to only allow expected characters and formats. - Web Application Firewall (WAF): Deploy a Web Application Firewall (WAF) to detect and block malicious requests targeting the Host header. Configure the WAF to filter out suspicious characters and patterns.
- Consider Alternatives: If possible, consider migrating away from the vulnerable Hush Framework version 2.0 to a more actively maintained and secure framework.
- Monitor for Suspicious Activity: Implement monitoring and logging to detect any suspicious activity related to the Host header. Look for unusual characters or patterns in the Host header, as well as any unexpected behavior of the application.
References
GitHub Exploit Disclosure
VulDB Entry – Correlation ID
VulDB Entry – Vulnerability ID
