CVE-2008-1771 in Firefly Media Server
Summary
by MITRE
Integer overflow in the ws_getpostvars function in Firefly Media Server (formerly mt-daapd) 0.2.4.1 (0.9~r1696-1.2 on Debian) allows remote attackers to cause a denial of service (crash) and possibly execute arbitrary code via an HTTP POST request with a large Content-Length.
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Analysis
by VulDB Data Team • 08/09/2019
The CVE-2008-1771 vulnerability resides within the Firefly Media Server implementation, formerly known as mt-daapd, specifically in the ws_getpostvars function that handles HTTP POST requests. This critical flaw manifests as an integer overflow condition that occurs when processing HTTP requests with excessively large Content-Length headers, representing a fundamental security weakness in the server's input validation mechanisms. The vulnerability affects version 0.2.4.1 and the Debian package version 0.9~r1696-1.2, indicating this issue persisted across multiple release iterations of the media server software. The flaw stems from inadequate bounds checking in the processing of HTTP POST data, where the server fails to properly validate the size of incoming content before attempting to allocate memory resources.
The technical exploitation of this vulnerability occurs when a remote attacker crafts an HTTP POST request containing an oversized Content-Length value that exceeds the maximum representable value for the integer data type used in the ws_getpostvars function. When the server attempts to process this malformed request, the integer overflow causes unpredictable behavior in the memory allocation routines, leading to either a crash of the media server process or potentially allowing an attacker to execute arbitrary code on the affected system. This type of vulnerability falls under CWE-190, which specifically addresses integer overflow conditions that can result in memory corruption and arbitrary code execution. The overflow occurs during the parsing of HTTP POST variables, where the server's internal handling of content size parameters fails to account for potential overflow scenarios, creating a path for malicious input to compromise system integrity.
The operational impact of this vulnerability extends beyond simple denial of service, as the potential for arbitrary code execution presents a significant security risk to systems running the affected Firefly Media Server software. Organizations utilizing this media server for audio streaming or digital media distribution face the risk of unauthorized access and system compromise, particularly in environments where the server is exposed to untrusted network traffic. The vulnerability's exploitation requires minimal effort from attackers, as they only need to craft a single HTTP POST request with a carefully constructed Content-Length header to trigger the overflow condition. This makes the vulnerability particularly dangerous in automated attack scenarios, where malicious actors could leverage it for persistent system compromise. The attack surface is further expanded by the fact that Firefly Media Server is often deployed in home and small office environments where security monitoring may be limited, making exploitation more likely to go unnoticed.
Mitigation strategies for CVE-2008-1771 should prioritize immediate patching of the affected Firefly Media Server installations, as this vulnerability has been addressed in subsequent software releases. Organizations should implement network-level restrictions to limit access to the media server's HTTP endpoints, particularly by blocking or filtering HTTP POST requests that contain suspicious Content-Length values. The implementation of input validation controls at the network perimeter can provide additional defense-in-depth measures, ensuring that malformed requests are identified and blocked before reaching the vulnerable application. Security monitoring should be enhanced to detect unusual patterns in HTTP POST request processing, particularly those involving unusually large content sizes that could indicate exploitation attempts. System administrators should also consider implementing intrusion detection systems that can identify and alert on known attack signatures related to this vulnerability, while maintaining regular security updates to prevent similar issues from arising in other components of their media streaming infrastructure. The vulnerability demonstrates the critical importance of proper integer handling and bounds checking in network applications, aligning with ATT&CK technique T1203 which covers exploitation of input validation flaws to achieve arbitrary code execution.