CVE-2009-4761 in RM Downloader
Summary
by MITRE
Stack-based buffer overflow in Mini-stream RM Downloader allows remote attackers to execute arbitrary code via a long string in a .smi file.
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Analysis
by VulDB Data Team • 05/03/2026
The CVE-2009-4761 vulnerability represents a critical stack-based buffer overflow flaw discovered in Mini-stream RM Downloader software, which falls under the broader category of software security weaknesses categorized by CWE-121. This vulnerability specifically affects the handling of .smi file formats, which are commonly used for subtitle data in multimedia applications. The flaw exists within the software's parsing mechanism for these subtitle files, creating an exploitable condition that can be leveraged by remote attackers to execute arbitrary code on vulnerable systems.
The technical implementation of this vulnerability occurs when the Mini-stream RM Downloader processes a maliciously crafted .smi file containing an excessively long string that exceeds the allocated buffer space on the stack. This buffer overflow condition arises from inadequate input validation and bounds checking within the application's file parsing routines. When the software attempts to store the oversized string data into a fixed-size stack buffer, the excess data overflows into adjacent memory locations, potentially corrupting the stack frame and allowing attackers to overwrite critical program execution elements such as return addresses or function pointers.
The operational impact of this vulnerability extends beyond simple code execution, as it provides attackers with the capability to gain full control over affected systems running the vulnerable software. This remote code execution vulnerability creates a significant risk for users who may unknowingly download and process malicious subtitle files from untrusted sources. The attack vector is particularly concerning because .smi files are commonly used in multimedia applications and are often automatically downloaded as part of media playback experiences, making exploitation more likely. The vulnerability affects systems where Mini-stream RM Downloader is installed and actively processes subtitle files, potentially compromising user systems through social engineering or automated download mechanisms.
From a cybersecurity perspective, this vulnerability aligns with ATT&CK technique T1059.007 for command and control communication and T1203 for exploitation for arbitrary code execution. Organizations should implement immediate mitigations including software updates from the vendor, network segmentation to limit exposure, and user education regarding the dangers of downloading content from untrusted sources. Additionally, security monitoring should focus on detecting unusual file processing activities and potential exploitation attempts. The vulnerability demonstrates the importance of proper input validation and memory safety practices in multimedia applications, as highlighted by industry standards that emphasize the need for robust buffer management and secure coding practices to prevent such critical security flaws from being exploited in real-world scenarios.