CVE-2019-1833
Cisco Firepower Threat Defense Software SSL/TLS Policy Bypass Vulnerability
A vulnerability in the Secure Sockets Layer (SSL)/Transport Layer Security (TLS) protocol parser of Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to bypass configured policies. The vulnerability is due to improper parsing of specific attributes in a TLS packet header. An attacker could exploit this vulnerability by sending malicious TLS messages to the affected system. A successful exploit could allow the attacker to bypass the configured policies for the system, which could allow traffic to flow through without being inspected.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- Low
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
Cisco Firepower Threat Defense Software SSL/TLS Policy Bypass Vulnerability
A vulnerability in the Secure Sockets Layer (SSL)/Transport Layer Security (TLS) protocol parser of Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to bypass configured policies. The vulnerability is due to improper parsing of specific attributes in a TLS packet header. An attacker could exploit this vulnerability by sending malicious TLS messages to the affected system. A successful exploit could allow the attacker to bypass the configured policies for the system, which could allow traffic to flow through without being inspected.
- Record
CVE-2019-1833- CVSS 3.0
- 5.8 Medium
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N - Weakness
- CWE-693
- Updated
- 2026-11-02
EUVDEUVD-2019-10390
A vulnerability in the Secure Sockets Layer (SSL)/Transport Layer Security (TLS) protocol parser of Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to bypass configured policies. The vulnerability is due to improper parsing of specific attributes in a TLS packet header. An attacker could exploit this vulnerability by sending malicious TLS messages to the affected system. A successful exploit could allow the attacker to bypass the configured policies for the system, which could allow traffic to flow through without being inspected.
- Record
EUVD-2019-10390- CVSS 3.0
- 5.8 Medium
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N - Updated
- 2026-11-03
GitHub AdvisoriesGHSA-6ffw-22x4-4x3r
A vulnerability in the Secure Sockets Layer (SSL)/Transport Layer Security (TLS) protocol parser...
A vulnerability in the Secure Sockets Layer (SSL)/Transport Layer Security (TLS) protocol parser of Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to bypass configured policies. The vulnerability is due to improper parsing of specific attributes in a TLS packet header. An attacker could exploit this vulnerability by sending malicious TLS messages to the affected system. A successful exploit could allow the attacker to bypass the configured policies for the system, which could allow traffic to flow through without being inspected.
- Record
GHSA-6ffw-22x4-4x3r- CVSS 3.0
- 5.8 Medium
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N - Weakness
- CWE-693
- Updated
- 2026-11-02
NVD
A vulnerability in the Secure Sockets Layer (SSL)/Transport Layer Security (TLS) protocol parser of Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to bypass configured policies. The vulnerability is due to improper parsing of specific attributes in a TLS packet header. An attacker could exploit this vulnerability by sending malicious TLS messages to the affected system. A successful exploit could allow the attacker to bypass the configured policies for the system, which could allow traffic to flow through without being inspected.
- Record
CVE-2019-1833- CVSS 3.0
- 5.8 Medium
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N - CVSS 2.0
- 5.0 Medium
AV:N/AC:L/Au:N/C:N/I:P/A:N - Weakness
- CWE-693
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases, published | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2019-1833 is a medium vulnerability (CVSS 5.8) in Cisco Firepower Threat Defense Software, published May 16, 2019. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.71%, the 77th percentile. No source names a fixed version.