CVE-2019-1981: A vulnerability in the normalization functionality of Cisco Firepower Threat Defense Software, Cisco FirePOWER

This month

MEDIUM 5.8REMOTEMITIGATEUPGRADEMITIGATE

CVE-2019-1981 is a medium-severity flaw (CVSS 5.8) affecting firepower services software for asa, secure firewall management center, secure firewall threat defense. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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 pa

Why this priority

Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	5.8 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	1.0% (top 36%)
CISA exploited list	No
Weakness	CWE-264, CWE-20
Published	2019-11-05
Last modified	2026-08-11

Publisher (CNA): Cisco Systems, Inc. · Vendor: cisco

Last updated 2026-08-11 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2019-11-05 20:15 UTCPublished CVE record published
2026-08-11 19:37 UTCUpdated Record last modified

cisco firepower services software for asa MITIGATE

Affected: all versions

Fixed in: no fixed release known

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy firepower-services-software-for-asa || rpm -q firepower-services-software-for-asa || firepower-services-software-for-asa --version

No fixed or unaffected release known

Apply the vendor mitigation from the advisory, disable the affected feature, or restrict network access.

cisco secure firewall management center UPGRADE

Affected: >= 2.9.12 and <= 2.9.12.15 · >= 2.9.13 and <= 2.9.13.6 · >= 2.9.14.0 and <= 2.9.14.5 · 2.9.15 · 2.9.16

Fixed in: newer than 2.9.14.5

Safe to downgrade to: a release before 2.9.12

1. Check installed version

apt-cache policy secure-firewall-management-center || rpm -q secure-firewall-management-center || secure-firewall-management-center --version

2. UPGRADE to newer than 2.9.14.5 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade secure-firewall-management-center

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade secure-firewall-management-center

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 2.9.12 (Debian / Ubuntu)

apt-cache madison secure-firewall-management-center sudo apt install secure-firewall-management-center=<VERSION_BEFORE_2.9.12> sudo apt-mark hold secure-firewall-management-center

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list secure-firewall-management-center sudo dnf downgrade secure-firewall-management-center-<VERSION_BEFORE_2.9.12> sudo dnf versionlock add secure-firewall-management-center

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

cisco secure firewall threat defense MITIGATE

Affected: all versions

Fixed in: no fixed release known

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy secure-firewall-threat-defense || rpm -q secure-firewall-threat-defense || secure-firewall-threat-defense --version

No fixed or unaffected release known

Apply the vendor mitigation from the advisory, disable the affected feature, or restrict network access.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2019-1981?

firepower services software for asa: mitigate or apply the listed mitigation; secure firewall management center: upgrade to newer than 2.9.14.5; secure firewall threat defense: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2019-1981 being exploited?

CVE-2019-1981 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2019-1981 affect?

CVE-2019-1981 affects firepower services software for asa, secure firewall management center, secure firewall threat defense. Severity is medium (CVSS 5.8). 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 bypa

How urgent is CVE-2019-1981?

Priority 41/100. Remotely exploitable, no login, no user action

Software pages

Cisco vulnerabilities

Related CVEs

CVE-2019-1978 MEDIUM 5.8 MITIGATE UPGRADE A vulnerability in the stream reassembly component of Cisco Firepower Threat Defense Software, Cisco FirePOWER
CVE-2019-1980 MEDIUM 5.3 MITIGATE UPGRADE A vulnerability in the protocol detection component of Cisco Firepower Threat Defense Software, Cisco FirePOWE
CVE-2019-1982 MEDIUM 5.3 MITIGATE DOWNGRADE A vulnerability in the HTTP traffic filtering component of Cisco Firepower Threat Defense Software, Cisco Fire
CVE-2022-20927 HIGH 7.7 MITIGATE UPGRADE A vulnerability in the SSL/TLS client of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower
CVE-2022-20918 HIGH 7.5 MITIGATE UPGRADE A vulnerability in the Simple Network Management Protocol (SNMP) access controls for Cisco FirePOWER Software

References

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