GHSA-f3xg-63wg-hjw4: FreeSWITCH: Out-of-bounds read in RTCP NACK feedback parsing

FreeSWITCH is a Software Defined Telecom Stack enabling the digital transformation from proprietary telecom switches to a software implementation that runs on any commodity hardware. Prior to 1.11.2, processrtcpreport() used an RTPFB NACK packet's declared RTCP header length as its feedback-entry loop bound instead of the datagram length already validated by the caller. A short packet with an oversized declaration could drive reads far beyond the fixed 16 KiB receive buffer. Any peer able to send RTCP to an active video call can reach the flaw, including calls where remote SDP enables video RTCP even though the SIP profile has no explicit RTCP interval configured. The out-of-bounds read can crash FreeSWITCH and terminate every active call, but supplies no write primitive and does not echo the read values to the sender. This issue is fixed in version 1.11.2.