CVE-2022-29189 in DTLS
Summary
by MITRE • 05/21/2022
Pion DTLS is a Go implementation of Datagram Transport Layer Security. Prior to version 2.1.4, a buffer that was used for inbound network traffic had no upper limit. Pion DTLS would buffer all network traffic from the remote user until the handshake completes or timed out. An attacker could exploit this to cause excessive memory usage. Version 2.1.4 contains a patch for this issue. There are currently no known workarounds available.
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Analysis
by VulDB Data Team • 01/23/2026
The vulnerability identified as CVE-2022-29189 affects Pion DTLS, a popular Go implementation of the Datagram Transport Layer Security protocol used for securing real-time communications. This implementation is widely utilized in WebRTC applications and other real-time streaming systems where secure datagram communication is essential. The flaw represents a classic resource exhaustion vulnerability that specifically targets the memory management mechanisms within the DTLS handshake process.
The technical root cause of this vulnerability lies in the absence of bounds checking for inbound network traffic buffers within the Pion DTLS library. Prior to version 2.1.4, the implementation maintained an unbounded buffer to store all incoming network packets from remote peers until either the DTLS handshake completed successfully or timed out. This design flaw allows an attacker to continuously send network packets to the target system without any upper limit on the buffer size. The buffer accumulates all incoming data regardless of the handshake state, creating a memory consumption issue that grows indefinitely as more packets are received.
From an operational impact perspective, this vulnerability enables a remote attacker to perform a memory exhaustion attack against systems utilizing Pion DTLS. The attack does not require authentication or specific privileges, making it particularly dangerous in environments where DTLS is used for peer-to-peer communications or real-time applications. The excessive memory usage can lead to system instability, application crashes, or even complete system resource exhaustion, potentially causing denial of service conditions for legitimate users. This vulnerability directly maps to CWE-772, which describes "Missing Release of Resource after Effective Lifetime," and represents a significant security risk in real-time communication systems.
The attack vector for this vulnerability is straightforward and can be executed by any remote attacker who can establish a connection to the vulnerable system. The attacker simply needs to maintain an open connection while continuously sending network packets to the DTLS endpoint, causing the buffer to grow without bounds. The severity of this issue is amplified because the buffer is not only unbounded but also persists until the connection times out or the handshake completes, providing attackers with extended time windows to consume system resources. This behavior aligns with ATT&CK technique T1499.004, which describes "Endpoint Termination: Service Stop," though in this case the impact is more subtle and resource-based rather than direct service termination.
Systems using Pion DTLS version 2.1.3 or earlier are at risk, particularly those deployed in environments with limited memory resources or high connection volumes. The vulnerability affects any application that relies on Pion DTLS for secure datagram communication, including WebRTC implementations, VoIP systems, and real-time collaboration tools. Organizations should prioritize updating to version 2.1.4 or later to remediate this vulnerability, as no effective workarounds exist to mitigate the issue without patching the underlying library. The patch implemented in version 2.1.4 addresses the buffer management issue by introducing proper bounds checking and limiting the amount of data that can be buffered during the DTLS handshake process. This remediation aligns with security best practices for preventing resource exhaustion attacks and ensures that the library maintains predictable memory usage patterns during normal operations.