CVE-2015-8271 in RTMPDump
Summary
by MITRE
The AMF3CD_AddProp function in amf.c in RTMPDump 2.4 allows remote RTMP Media servers to execute arbitrary code.
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Analysis
by VulDB Data Team • 08/30/2020
The vulnerability identified as CVE-2015-8271 represents a critical remote code execution flaw within RTMPDump 2.4, specifically within the AMF3CD_AddProp function located in the amf.c file. This issue stems from improper input validation and handling of serialized data structures used in the Action Message Format version 3 protocol, which is fundamental to Adobe Flash Media Server communications. The vulnerability exists in the way the software processes property additions during AMF3 deserialization, creating a potential attack vector for malicious RTMP media servers to inject and execute arbitrary code on systems running vulnerable versions of RTMPDump.
The technical exploitation of this vulnerability occurs through the manipulation of serialized AMF3 data structures that are transmitted over RTMP connections. When the AMF3CD_AddProp function processes incoming property data, it fails to properly validate the size and structure of the serialized input, allowing attackers to craft malicious payloads that trigger buffer overflows or memory corruption conditions. This flaw enables remote attackers to inject code that executes within the context of the RTMPDump process, potentially leading to complete system compromise. The vulnerability aligns with CWE-121, which describes heap-based buffer overflow conditions, and specifically demonstrates how improper input handling in serialization routines can lead to arbitrary code execution.
The operational impact of CVE-2015-8271 extends beyond simple remote code execution, as it can facilitate a wide range of malicious activities including data exfiltration, system reconnaissance, and persistent backdoor installation. Attackers can leverage this vulnerability to gain unauthorized access to systems that utilize RTMPDump for media streaming operations, particularly those in enterprise environments where Flash Media Server implementations are common. The vulnerability affects not only the immediate system but can also enable lateral movement within networks where RTMP protocols are used for media delivery, making it particularly dangerous in broadcast and streaming environments.
Organizations should implement immediate mitigations including updating to patched versions of RTMPDump, implementing network segmentation to restrict RTMP traffic, and deploying intrusion detection systems that can identify anomalous AMF3 data patterns. The vulnerability demonstrates the importance of proper input validation in serialization libraries and aligns with ATT&CK technique T1059.007 for command and scripting interpreter, as successful exploitation would allow adversaries to execute commands on compromised systems. Security teams should also consider implementing application whitelisting policies and monitoring for suspicious RTMP connection patterns that could indicate exploitation attempts. The issue underscores the critical need for comprehensive security testing of serialization routines in network protocols and highlights the potential for supply chain vulnerabilities when using third-party media streaming libraries.