CVE-2025-57783 in Hiawatha
Summary
by MITRE • 01/26/2026
Improper header parsing may lead to request smuggling has been identified in Hiawatha webserver version 11.7 which allows an unauthenticated attacker to access restricted resources managed by Hiawatha webserver.
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Analysis
by VulDB Data Team • 02/18/2026
The vulnerability identified as CVE-2025-57783 represents a critical security flaw in the Hiawatha webserver version 11.7 that stems from improper header parsing mechanisms. This weakness creates a pathway for request smuggling attacks, where an attacker can manipulate HTTP headers to bypass access controls and gain unauthorized access to protected resources within the webserver environment. The vulnerability specifically targets the webserver's handling of HTTP request headers, which are critical components in determining how requests are processed and routed through the server infrastructure. When headers are not properly validated or parsed, they can be exploited to craft malicious requests that appear legitimate to the server while actually containing instructions that manipulate the request flow.
The technical implementation of this vulnerability lies in the webserver's failure to correctly interpret and validate HTTP headers during request processing. This improper header parsing allows attackers to inject or modify header values in ways that can cause the server to process requests differently than intended. The flaw operates at the HTTP protocol level where multiple header fields are involved in determining request boundaries, content length, and processing behavior. Attackers can exploit this by crafting requests with malformed or overlapping header values that confuse the server's request parsing logic, potentially leading to situations where the server processes different parts of the same request in different contexts or routes requests to unintended destinations.
From an operational impact perspective, this vulnerability creates significant risks for organizations relying on Hiawatha webserver version 11.7 for their web hosting services. The ability to access restricted resources without authentication represents a severe privilege escalation opportunity that could allow attackers to bypass security controls and gain access to sensitive data, administrative interfaces, or other protected resources. The attack vector does not require authentication, making it particularly dangerous as it can be exploited by anyone who can send requests to the vulnerable server. This vulnerability undermines the fundamental security model of web applications by allowing unauthorized access to resources that should be protected by access control mechanisms.
The implications of this vulnerability align with CWE-444, which addresses improper header parsing and HTTP request smuggling, and can be mapped to ATT&CK technique T1190 for exploiting vulnerabilities in web applications. Organizations using Hiawatha webserver version 11.7 should immediately implement mitigations including upgrading to a patched version of the software, implementing additional header validation mechanisms, and monitoring for suspicious header patterns in web server logs. Network segmentation and web application firewalls can provide additional layers of protection while the primary software patch is being deployed. Regular security auditing of header parsing mechanisms and implementing strict input validation for all HTTP headers will help prevent similar vulnerabilities from being exploited in the future. The vulnerability demonstrates the critical importance of proper HTTP protocol implementation in web servers and the potential consequences when header validation is insufficient or improperly implemented in web application security architectures.