Firepower Services Software For AsaApplication · Cisco
CVE-2019-1981
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedA 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.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · moderate confidenceA filter bypass vulnerability in Cisco Firepower products allows attackers to circumvent security filtering by sending obfuscated text-based payloads that are not properly normalized. The normalization functionality fails to properly process specifically crafted obfuscated data, allowing malicious payloads to pass through the affected device to protected systems.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data
Firepower Services Software For AsaApplication
all versions
Secure Firewall Management CenterApplication
>= 2.9.12, <= 2.9.12.15>= 2.9.13, <= 2.9.13.6>= 2.9.14.0, <= 2.9.14.5= 2.9.15= 2.9.16
Secure Firewall Threat DefenseApplication
all versionsCVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Changed
- Confidentiality
- None
- Integrity
- Low
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Identify the installed Cisco Firepower product and versionRun 'show version' on the device CLI, or check the Management Center web UI under System > Updates to confirm the exact product name (Firepower Services for ASA, Firepower Threat Defense, or Secure Firewall Management Center) and its current software versionAffected if The product is any version of Firepower Services for ASA or Firepower Threat Defense, or Secure Firewall Management Center version 2.9.12 through 2.9.12.15, 2.9.13 through 2.9.13.6, 2.9.14.0 through 2.9.14.5, 2.9.15, or 2.9.16
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Confirm security filtering or IPS is enabledCheck the access control policy or intrusion policy settings in the Firepower Management Center under Policies > Access Control, or run 'show running-config policy-map' on the Firepower Threat Defense CLI to see if filtering is activeAffected if Security filtering or intrusion prevention is configured and actively processing traffic, as the bypass only affects normalization of text-based payloads during inspection
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Review traffic logs for bypass indicatorsExamine Firepower event logs (under Analysis > Events) and connection logs for any suspicious patterns where text-based payloads may have circumvented normalization, particularly look for unexpected traffic reaching protected hosts despite filtering policiesAffected if Traffic logs show connections that should have been blocked by filtering rules but were allowed through, especially if the payloads contain obfuscated text patterns
You are affected if you run any version of Firepower Services for ASA or Firepower Threat Defense, or run Secure Firewall Management Center within the specified version ranges, and you have security filtering enabled that inspects text-based traffic.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
From vendor dataApply the vendor patch from Cisco for Firepower Threat Defense, FirePOWER Services for ASA, and Firepower Management Center. In the interim, implement additional layer 7 inspection or deploy complementary filtering to detect obfuscation techniques.
Fix this in Firepower Services Software For Asa
Scoped from the published advisory
- Consultation4.0 h
- Implementation8.0 h
- Testing6.0 h
- Review / QA4.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $6,176.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2019-1981 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2019-1981 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
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