CVE-2020-3226: Cisco IOS and IOS XE Software Session Initiation Protocol Denial of Service Vulnerability

Severity: high (CVSS 8.6 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.6% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2020-06-03 · updated 2026-06-17
Weakness: CWE-20

Description

A vulnerability in the Session Initiation Protocol (SIP) library of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to trigger a reload of an affected device, resulting in a denial of service (DoS) condition. The vulnerability is due to insufficient sanity checks on received SIP messages. An attacker could exploit this vulnerability by sending crafted SIP messages to an affected device. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a denial of service condition.

Affected products

Cisco IOS: 15.0(2)sg11a, 15.3(3)jaa1, 15.3(3)jpi, 15.3(3)jpj, 15.3(3)m, 15.3(3)m1 (+97)
Cisco IOS XE: 3.10.0s, 3.10.1s, 3.10.2as, 3.10.2s, 3.10.2ts, 3.10.3s (+151)

References

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