CVE-2020-28361: Kamailio

Medium severity, CVSS 5.4. EPSS: 1.1% chance of exploitation in the next 30 days.

Kamailio before 5.4.0, as used in Sip Express Router (SER) in Sippy Softswitch 4.5 through 5.2 and other products, allows a bypass of a header-removal protection mechanism via whitespace characters. This occurs in the remove_hf function in the Kamailio textops module. Particular use of remove_hf in Sippy Softswitch may allow skilled attacker having a valid credential in the system to disrupt internal call start/duration accounting mechanisms leading potentially to a loss of revenue.

Affected products

• Kamailio Kamailio: before 5.4.0 (fixed in 5.4.0)

Published 2020-11-18. Last modified 2026-06-17.