CVE-2019-1691: Cisco Firepower Threat Defense Software SSL or TLS Denial of Service Vulnerability

Published Feb 20, 2019
·
Updated

A vulnerability in the detection engine of Cisco Firepower Threat Defense Software could allow an unauthenticated, remote attacker to cause the unexpected restart of the SNORT detection engine, resulting in a denial of service (DoS) condition. The vulnerability is due to the incomplete error handling of the SSL or TLS packet header during the connection establishment. An attacker could exploit this vulnerability by sending a crafted SSL or TLS packet during the connection handshake. An exploit could allow the attacker to cause the SNORT detection engine to unexpectedly restart, resulting in a partial DoS condition while the detection engine restarts. Versions prior to 6.2.3.4 are affected.

Affected Software

2 affected components
Cisco Firepower Threat Defense<6.2.3.4
Cisco Secure Firewall Threat Defense<6.2.3.4

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade Cisco Firepower Threat Defense Software to a version that resolves this vulnerability.

    Fixed in 6.2.3.4

Event History

Feb 21, 2019
CVE Published
08:29 PM
Data Sourced
via NVD·08:29 PM
DescriptionSeverityWeaknessAffected Software
CVE Published
via MITRE·09:00 PM
Data Sourced
via MITRE·09:00 PM
DescriptionSeverityWeakness

Frequently Asked Questions

1

What is the severity of CVE-2019-1691?

CVE-2019-1691 has a high severity rating due to its potential to cause a denial of service.

2

How do I fix CVE-2019-1691?

To mitigate CVE-2019-1691, upgrade Cisco Firepower Threat Defense Software to the latest version beyond 6.2.3.4.

3

What causes the vulnerability in CVE-2019-1691?

CVE-2019-1691 is caused by an issue in the detection engine of Cisco Firepower Threat Defense Software.

4

Who is affected by CVE-2019-1691?

CVE-2019-1691 affects users of Cisco Firepower Threat Defense Software versions below 6.2.3.4.

5

What are the risks associated with CVE-2019-1691?

The main risk associated with CVE-2019-1691 is a denial of service condition due to the unexpected restart of the SNORT detection engine.

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