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CVE-2019-1981

Cisco Firepower Threat Defense Software NULL Character Obfuscation Detection Bypass Vulnerability

Medium5.8EPSS 1.0%
Published
Updated
Reserved
Assigned by
cisco

Description

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.

Scores

CVSS scores of CVE-2019-1981, by who scored it
Scored byCVSSScoreVector
ciscoCNA (assigner)3.0Medium5.8CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N
NVDNVD · Modified3.1Medium5.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N
EPSS (exploitation in 30 days)
1.0% · top 36% of all CVEs (2 Nov 2026)
CISA SSVC
Exploitation: none · Automatable: yes · Technical impact: partial

Loading the EPSS history…

The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 5.8.

Weakness

Affected products

  • Cisco · Cisco Firepower Threat Defense Software

    • affected unspecified – < n/a

What to do

Exploitation: The Cisco Product Security Incident Response Team (PSIRT) is not aware of any public announcements or malicious use of the vulnerability that is described in this advisory.

References (1)

Sources

The same CVE in the primary databases and aggregators, to check against.

Record last updated .