CVE-2021-44718: 
NixOS vulnerability analysis and mitigation

CVE-2021-44718 affects wolfSSL through version 5.0.0, where a potential denial of service (DoS) attack could occur on wolfSSL clients due to processing hello packets of the incorrect side. This vulnerability specifically affects connections using TLS v1.2 or lower that have been compromised by a man-in-the-middle attack (wolfSSL Security).

The vulnerability is related to TLS 1.3 support and involves incorrect handling of hello packets. The issue was discovered by security researchers James Henderson, Mathy Vanhoef, Chris M. Stone, Sam L. Thomas, Nicolas Bailleut, and Tom Chothia from the University of Birmingham, KU Leuven, and ENS Rennes (wolfSSL Security).

The vulnerability allows attackers to potentially cause a denial of service condition on wolfSSL clients. However, the impact is limited as it only affects TLS v1.2 or lower connections and requires the connection to be already compromised by a man-in-the-middle attack (wolfSSL Security).

The vulnerability was fixed in wolfSSL version 5.1.0. Users running affected versions should upgrade to version 5.1.0 or later to mitigate this vulnerability (wolfSSL Security).