Provide references for CVE-2021-43611.
Where can I find more information about CVE-2021-43611?
References are available at: https://github.com/BelledonneCommunications/belle-sip/commit/d3f0651531e45e91c2e60f3a16a8b612802e5d2d, https://github.com/BelledonneCommunications/belle-sip/compare/5.0.18...5.0.20.