What’s Vulnerable › Vulnerabilities

CVE-2021-33056

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2021-08-12 · updated 2026-06-17
• Weakness: CWE-444

Description

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.

Affected products

• Linphone Belle-Sip: before 4.5.20 — fixed in 4.5.20

How to fix

Upgrade to a fixed version: Linphone Belle-Sip 4.5.20. Check the vendor advisory for mitigations.

References

• https://github.com/BelledonneCommunications/belle-sip/commit/116e3eb48fe43ea63eb9f3c4b4b30c48d58d6ff0
• https://github.com/BelledonneCommunications/belle-sip/compare/4.5.15...4.5.20
• https://github.com/BelledonneCommunications/belle-sip/commit/116e3eb48fe43ea63eb9f3c4b4b30c48d58d6ff0
• https://github.com/BelledonneCommunications/belle-sip/compare/4.5.15...4.5.20

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