CVE-2025-53399 in rtpengine
Summary
by MITRE • 08/01/2025
In Sipwise rtpengine before 13.4.1.1, an origin-validation error in the endpoint-learning logic of the media-relay core allows remote attackers to inject or intercept RTP/SRTP media streams via RTP packets (except when the relay is configured for strict source and learning disabled). Version 13.4.1.1 fixes the heuristic mode by limiting exposure to the first five packets, and introduces a recrypt flag that fully prevents SRTP attacks when both mitigations are enabled.
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Analysis
by VulDB Data Team • 08/01/2025
The vulnerability identified as CVE-2025-53399 represents a critical origin-validation flaw within the Sipwise rtpengine media relay system affecting versions prior to 13.4.1.1. This issue resides in the endpoint-learning logic of the media-relay core, which is responsible for managing real-time transport protocol and secure real-time transport protocol media streams. The flaw enables remote attackers to manipulate media stream delivery by injecting or intercepting RTP/SRTP packets, fundamentally compromising the integrity and confidentiality of voice communications. The vulnerability specifically targets the validation mechanisms that should ensure media streams originate from legitimate sources, creating a pathway for malicious actors to establish unauthorized connections within the communication infrastructure.
The technical implementation of this vulnerability stems from insufficient validation of packet origins within the endpoint-learning process. When rtpengine receives RTP packets, it should verify the authenticity of source addresses and maintain proper session state to prevent unauthorized media stream manipulation. However, the flawed logic allows attackers to exploit the learning mechanism by sending crafted packets that bypass normal validation procedures. This weakness particularly affects scenarios where the relay operates in heuristic mode without strict source validation, creating a window of opportunity for attackers to inject malicious media streams or intercept legitimate communications. The vulnerability manifests as an insufficient input validation issue that can be categorized under CWE-20, which addresses improper input validation in software systems.
The operational impact of this vulnerability extends beyond simple media stream manipulation to potentially compromise entire communication infrastructures. Attackers could exploit this flaw to redirect voice traffic to unauthorized endpoints, conduct man-in-the-middle attacks on voice communications, or inject malicious audio content into ongoing calls. The severity increases when considering that rtpengine typically operates as a core component in VoIP infrastructure, where media relay functionality is critical for maintaining communication integrity. Organizations relying on Sipwise rtpengine for voice services face significant risks including unauthorized surveillance, call interception, and potential disruption of critical communication services. The vulnerability affects not only the confidentiality of voice communications but also the overall trustworthiness of the media relay system.
The remediation implemented in version 13.4.1.1 addresses this vulnerability through two primary mitigations that align with established security best practices. The first mitigation limits exposure to the initial five packets received by the system, effectively reducing the attack window and preventing prolonged exploitation opportunities. This approach follows principles similar to those recommended in the ATT&CK framework for network traffic analysis, where limiting initial packet processing can prevent malicious activity from establishing persistent connections. The second mitigation introduces a recrypt flag that provides complete protection against SRTP attacks when both security measures are enabled. This dual-layer approach demonstrates adherence to defense-in-depth principles, ensuring that even if one mitigation fails, the other provides continued protection. The fix represents a comprehensive solution that addresses both the root cause of the origin-validation error and provides operational controls that can be configured based on organizational security requirements.
Organizations should prioritize upgrading to version 13.4.1.1 or later to address this vulnerability, as the attack surface remains significant for systems operating with heuristic mode enabled and learning disabled. The remediation process should include configuration review to ensure that both the packet limiting mechanism and recrypt flag are properly enabled. Security teams should monitor for potential exploitation attempts and consider implementing additional network-level controls such as packet filtering rules and traffic analysis to detect anomalous media stream behavior. The vulnerability highlights the importance of proper session validation in real-time communication systems and underscores the need for continuous security assessment of media relay components in VoIP infrastructure.