CVE-2019-1981: Cisco Firepower Threat Defense Software NULL Character Obfuscation Detection Bypass Vulnerability

Published Nov 5, 2019
·
Updated

A vulnerability in the normalization functionality of Cisco Firepower Threat Defense Software, Cisco FirePOWER Services Software for ASA, and Cisco Firepower Management Center Software could allow an unauthenticated, remote attacker to bypass filtering protections. The vulnerability is due to insufficient normalization of a text-based payload. An attacker could exploit this vulnerability by sending traffic that contains specifically obfuscated payloads through an affected device. An exploit could allow the attacker to bypass filtering and deliver malicious payloads to protected systems that would otherwise be blocked.

Affected Software

12 affected components
Cisco FirePOWER Services Software for ASA
Cisco Firepower Threat Defense
Cisco Secure Firewall Management Center>=2.9.12<=2.9.12.15
Cisco Secure Firewall Management Center>=2.9.13<=2.9.13.6
Cisco Secure Firewall Management Center>=2.9.14.0<=2.9.14.5
Cisco Secure Firewall Management Center=2.9.15
Cisco Secure Firewall Management Center=2.9.16
Cisco FirePOWER Management Center>=2.9.12<=2.9.12.15
Cisco FirePOWER Management Center>=2.9.13<=2.9.13.6
Cisco FirePOWER Management Center>=2.9.14.0<=2.9.14.5
Cisco FirePOWER Management Center=2.9.15
Cisco FirePOWER Management Center=2.9.16

Event History

Nov 5, 2019
CVE Published
via MITRE·07:35 PM
Data Sourced
via MITRE·07:35 PM
DescriptionSeverityWeakness
Data Sourced
via NVD·08:15 PM
DescriptionSeverityWeaknessAffected Software
Free Weekly Intel

Don't miss critical vulnerabilities

Join thousands of security professionals who receive our weekly digest of trending CVEs, zero-days, and exploited vulnerabilities.

No spam. Unsubscribe anytime.

Frequently Asked Questions

1

What is CVE-2019-1981?

CVE-2019-1981 is a vulnerability in the normalization functionality of Cisco Firepower Threat Defense Software, Cisco FirePOWER Services Software for ASA, and Cisco Firepower Management Center Software.

2

How can an attacker exploit CVE-2019-1981?

An unauthenticated, remote attacker can exploit CVE-2019-1981 to bypass filtering protections.

3

Which software versions are affected by CVE-2019-1981?

Cisco Firepower Management Center versions 2.9.12 to 2.9.12.15, 2.9.13 to 2.9.13.6, 2.9.14.0 to 2.9.14.5, 2.9.15, Cisco FirePOWER Services Software for ASA, and Cisco Firepower Threat Defense are affected by CVE-2019-1981.

4

What is the severity of CVE-2019-1981?

CVE-2019-1981 has a severity rating of medium with a CVSS score of 5.8.

5

How can I fix CVE-2019-1981?

Updating to the latest version of the affected software is recommended to fix CVE-2019-1981.

Contact

SecAlerts Pty Ltd.
132 Wickham Terrace
Fortitude Valley,
QLD 4006, Australia
info@secalerts.co
By using SecAlerts services, you agree to our services end-user license agreement. This website is safeguarded by reCAPTCHA and governed by the Google Privacy Policy and Terms of Service. All names, logos, and brands of products are owned by their respective owners, and any usage of these names, logos, and brands for identification purposes only does not imply endorsement. If you possess any content that requires removal, please get in touch with us.
© 2026 SecAlerts Pty Ltd.
ABN: 70 645 966 203, ACN: 645 966 203