Belledonne Belle-sip before 5.0.20 can crash applications such as Linphone via an invalid From header (request URI without a parameter) in an unauthenticated SIP message, a different issue than CVE-2021-33056.
Belledonne Belle-sip before 5.0.20 can crash applications such as Linphone via " \ " in the display name of a From header.
Belledonne Belle-sip before 4.5.20, as used in Linphone and other products, can crash via an invalid From header in a SIP message.
Belledonne Communications Linphone-Desktop is vulnerable to a NULL Dereference vulnerability, which could allow a remote attacker to create a denial-of-service condition.