CVE-2018-5130 in Firefox
Summary
by MITRE
When packets with a mismatched RTP payload type are sent in WebRTC connections, in some circumstances a potentially exploitable crash is triggered. This vulnerability affects Firefox ESR < 52.7 and Firefox < 59.
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Analysis
by VulDB Data Team • 11/26/2025
This vulnerability represents a critical memory safety issue within the WebRTC implementation of Mozilla Firefox browsers, specifically affecting versions prior to 52.7 ESR and 59.0 mainline releases. The flaw manifests when the WebRTC subsystem processes incoming media packets that contain mismatched RTP payload types, which can lead to unpredictable system behavior and potential exploitation. The vulnerability falls under the category of buffer overflows and memory corruption issues, with direct implications for browser security and stability. From a cybersecurity perspective, this represents a significant concern as WebRTC is widely used for real-time communication in web applications, making it a prime target for attackers seeking to compromise user systems through browser-based attacks.
The technical root cause of CVE-2018-5130 stems from inadequate input validation within the RTP (Real-time Transport Protocol) packet processing logic of Firefox's WebRTC implementation. When the browser receives media packets with inconsistent payload type identifiers, the parsing routine fails to properly handle the mismatched data, resulting in memory corruption that can trigger a crash condition. This type of vulnerability aligns with CWE-121, which describes stack-based buffer overflow conditions, and CWE-122, which covers heap-based buffer overflow scenarios. The flaw demonstrates poor error handling practices in network protocol processing, where the system does not adequately validate packet contents before attempting to process them, creating opportunities for attackers to craft malicious packets that exploit the parsing logic.
The operational impact of this vulnerability extends beyond simple browser crashes, as it presents a potential pathway for remote code execution in affected systems. Attackers could leverage this issue by sending specially crafted WebRTC packets to a victim's browser, potentially causing the application to crash or, in more sophisticated scenarios, executing arbitrary code on the target system. The vulnerability affects not only end-user browsers but also web applications that rely on WebRTC for communication features, making it particularly dangerous in enterprise environments where such applications are commonly deployed. This issue directly relates to ATT&CK technique T1203, which covers exploitation of remote services through network-based attacks, and T1059, which involves the execution of malicious code through compromised applications. The widespread use of WebRTC in modern web applications means that a successful exploitation could affect numerous users across different platforms and operating systems.
Organizations and users should prioritize immediate remediation by upgrading to Firefox versions 52.7 ESR or 59.0 and later, which contain patches addressing this memory corruption vulnerability. Security teams should implement network monitoring to detect and block suspicious WebRTC traffic patterns that might indicate exploitation attempts. Additional mitigations include deploying web application firewalls that can filter out malformed RTP packets and implementing strict browser security policies that limit WebRTC functionality in untrusted environments. The vulnerability underscores the importance of maintaining up-to-date software configurations and highlights the need for robust input validation in real-time communication protocols. Regular security assessments of WebRTC implementations and network traffic monitoring should be part of comprehensive cybersecurity strategies to prevent exploitation of similar memory safety issues in other browser components or web applications.