CVE-2004-1561 in Icecast
Summary
by MITRE
Buffer overflow in Icecast 2.0.1 and earlier allows remote attackers to execute arbitrary code via an HTTP request with a large number of headers.
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Analysis
by VulDB Data Team • 07/06/2025
The vulnerability identified as CVE-2004-1561 represents a critical buffer overflow flaw within Icecast 2.0.1 and earlier versions of the streaming media server software. This vulnerability specifically affects the HTTP request processing mechanism where the server fails to properly validate the number and size of headers in incoming HTTP requests. The flaw exists in the server's handling of malformed HTTP requests that contain an excessive number of headers, which causes the application to write beyond the allocated memory buffer, potentially leading to arbitrary code execution. This type of vulnerability falls under the Common Weakness Enumeration category CWE-121, which describes heap-based buffer overflow conditions where insufficient boundary checking allows attackers to overwrite adjacent memory locations.
The technical implementation of this vulnerability occurs when Icecast processes HTTP requests that contain an unusually large number of headers, typically exceeding the buffer size allocated for header storage. The server's HTTP parser does not implement proper bounds checking on the number of headers or their cumulative size, allowing an attacker to craft malicious requests that deliberately overflow the buffer allocated for header processing. When the server attempts to store these excessive headers in memory, the overflow can overwrite adjacent memory regions including return addresses, function pointers, or other critical control data structures. This memory corruption can be exploited to redirect program execution flow to malicious code injected by the attacker, effectively allowing remote code execution on the vulnerable system.
The operational impact of CVE-2004-1561 is severe and far-reaching within networked environments that rely on Icecast for media streaming services. Attackers can leverage this vulnerability to gain unauthorized access to servers running vulnerable versions of Icecast, potentially leading to complete system compromise. The remote nature of the attack means that exploitation can occur from anywhere on the internet without requiring local access or authentication, making it particularly dangerous for publicly accessible streaming servers. Organizations that deploy Icecast for radio broadcasting, live streaming, or media distribution services face significant risk of unauthorized access, data exfiltration, or service disruption. The vulnerability also aligns with ATT&CK technique T1203, which describes exploitation of remote services through buffer overflow attacks, and represents a classic example of how improper input validation can lead to privilege escalation and persistent access within target environments.
Mitigation strategies for CVE-2004-1561 primarily focus on immediate software updates and configuration hardening. Organizations should immediately upgrade to Icecast version 2.0.2 or later, where the buffer overflow vulnerability has been addressed through proper bounds checking and input validation. Additionally, implementing network-level protections such as firewalls, intrusion detection systems, and rate limiting can help reduce the attack surface by limiting the number of header fields that can be processed in a single request. Security configurations should include setting appropriate limits on header count and size, disabling unnecessary HTTP methods, and implementing robust logging to detect anomalous request patterns. The vulnerability also demonstrates the importance of following secure coding practices, particularly around memory management and input validation, as outlined in security standards such as OWASP Top Ten and the CERT Secure Coding Standards, which emphasize the need for proper buffer size validation and boundary checking in all network-facing applications.