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.
Conclusion & alert: CVE-2019-1981 is rated Moderate Risk (44.6/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 1.04%). Mandatory action: Review affected assets and schedule remediation.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
| # | Date | Old EPSS score | New EPSS score | Delta (New - Old) |
|---|---|---|---|---|
| 1 | 2026-06-15 | 0.40% | 1.04% | +0.64% |
| 2 | 2025-11-21 | 0.26% | 0.40% | +0.15% |
| 3 | 2025-11-18 | — | 0.26% | — |
Full EPSS history (12 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 5.8 | 3.1 | MEDIUM |
|
3.9 | 1.4 | [email protected] |
| 5.8 | 3.0 | MEDIUM |
|
3.9 | 1.4 | [email protected] |
| 5.0 | 2.0 | MEDIUM |
|
10.0 | 2.9 | [email protected] |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| cisco | firepower_services_software_for_asa | — | cpe:2.3:a:cisco:firepower_services_software_for_asa:*:*:*:*:*:*:*:* |
| cisco | firepower_threat_defense | — | cpe:2.3:a:cisco:firepower_threat_defense:*:*:*:*:*:*:*:* |
| cisco | secure_firewall_management_center | >= 2.9.12, <= 2.9.12.15 | cpe:2.3:a:cisco:secure_firewall_management_center:*:*:*:*:*:*:*:* |
| cisco | secure_firewall_management_center | >= 2.9.13, <= 2.9.13.6 | cpe:2.3:a:cisco:secure_firewall_management_center:*:*:*:*:*:*:*:* |
| cisco | secure_firewall_management_center | >= 2.9.14.0, <= 2.9.14.5 | cpe:2.3:a:cisco:secure_firewall_management_center:*:*:*:*:*:*:*:* |
| cisco | secure_firewall_management_center | 2.9.15 | cpe:2.3:a:cisco:secure_firewall_management_center:2.9.15:*:*:*:*:*:*:* |
| cisco | secure_firewall_management_center | 2.9.16 | cpe:2.3:a:cisco:secure_firewall_management_center:2.9.16:*:*:*:*:*:*:* |
| URL | Tags |
|---|---|
| https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190816-ftd-null | Vendor Advisory |