Firepower Services Software For AsaApplication · Cisco
CVE-2019-1978
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 stream reassembly component 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 improper reassembly of traffic streams. An attacker could exploit this vulnerability by sending crafted streams through an affected device. An exploit could allow the attacker to bypass filtering and deliver malicious requests 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 · high confidenceA vulnerability in the stream reassembly component of Cisco Firepower Threat Defense Software, FirePOWER Services Software for ASA, and Firepower Management Center Software allows an unauthenticated, remote attacker to bypass filtering protections by sending crafted streams through an affected device. The vulnerability stems from improper reassembly of traffic streams, enabling malicious requests to reach protected systems that would otherwise be blocked.
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 Cisco Firepower product and versionRun 'show version' on FTD/ASA devices, or check the Dashboard > Product License in the Firepower Management Center GUI to find the installed versionAffected if Product is Firepower Services for ASA, Firepower Threat Defense (any version), or Secure Firewall Management Center versions 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 intrusion prevention/filtering is enabledCheck the access control policy applied to the device: in FTD, run 'show access-list' and 'show policy-map'; in FMC, navigate to Policies > Access Control and verify an Intrusion Policy is attached to at least one ruleAffected if An access control policy with an intrusion policy or file/malware inspection is actively applied to interfaces handling traffic
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Verify stream reassembly is in useRun 'show service-policy' on FTD/ASA to confirm inspection is enabled, or in FMC check the Intrusion Policy settings under Policies > Intrusion > Inline Sets to confirm stream reassembly is activeAffected if Stream/tcp reassembly or any Snort-based inspection is enabled on the device
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Check for bypass indicators in traffic logsReview Snort/firewall logs for unexpected traffic patterns that passed through despite filtering rules, or run 'show conn' to inspect established connections that may have bypassed policyAffected if Traffic successfully reaches protected hosts through the Firepower device that should have been blocked by existing filtering rules
The environment is affected if the installed product is any version of Firepower Services for ASA or Firepower Threat Defense, or Secure Firewall Management Center versions 2.9.12-2.9.16, and stream-based filtering/intrusion inspection is actively applied to traffic flows.
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 relevant Cisco security patches for this vulnerability to affected Firepower deployments. Ensure proper testing of filtering functionality after patching to confirm the bypass is remediated.
Fix this in Firepower Services Software For Asa
Scoped from the published advisory
- Consultation4.0 h
- Implementation8.0 h
- Testing6.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $5,600.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2019-1978 — 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-2019-1978 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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A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
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