CVE-2021-21394 Denial of service (via resource exhaustion) due to improper input validation on third-party identifier endpoints

Synapse is a Matrix reference homeserver written in python pypi package matrix-synapse. Matrix is an ecosystem for open federated Instant Messaging and VoIP. In Synapse before version 1.28.0 Synapse is missing input validation of some parameters on the endpoints used to confirm third-party...

CVE-2021-21394

CVE-2021-21394 affects the Matrix Synapse reference homeserver (Python, matrix-synapse) prior to version 1.28.0. The issue is invalid input validation on endpoints used to confirm third-party identifiers, which could cause excessive disk space and memory usage leading to resource exhaustion. The ...