What’s Vulnerable › Vulnerabilities

CVE-2020-27507

• Severity: critical (CVSS 9.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.2% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2023-03-15 · updated 2026-06-17
• Weakness: CWE-120

Description

The Kamailio SIP before 5.5.0 server mishandles INVITE requests with duplicated fields and overlength tag, leading to a buffer overflow that crashes the server or possibly have unspecified other impact.

Affected products

• Kamailio: before 5.5.0 — fixed in 5.5.0

How to fix

Upgrade to a fixed version: Kamailio 5.5.0. Check the vendor advisory for mitigations.

References

• https://github.com/kamailio/kamailio/commit/ada3701d22b1fd579f06b4f54fa695fa988e685f
• https://github.com/kamailio/kamailio/issues/2503
• https://lists.debian.org/debian-lts-announce/2023/05/msg00030.html
• https://github.com/kamailio/kamailio/commit/ada3701d22b1fd579f06b4f54fa695fa988e685f
• https://github.com/kamailio/kamailio/issues/2503
• https://lists.debian.org/debian-lts-announce/2023/05/msg00030.html

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