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Firepower Threat DefenseApplication · Cisco

CVE-2018-15383

HIGH · 7.5 CVSS v3.1 Published 2018-10-05
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
84/100
Remediation priority · High
Remotely reachable No privileges Zero-click

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 · unedited
A vulnerability in the cryptographic hardware accelerator driver of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause an affected device to reload, resulting in a temporary denial of service (DoS) condition. The vulnerability exists because the affected devices have a limited amount of Direct Memory Access (DMA) memory and the affected software improperly handles resources in low-memory conditions. An attacker could exploit this vulnerability by sending a sustained, high rate of malicious traffic to an affected device to exhaust memory on the device. A successful exploit could allow the attacker to exhaust DMA memory on the affected device, which could cause the device to reload and result in a temporary DoS condition.

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 confidence

A vulnerability in the cryptographic hardware accelerator driver of Cisco ASA and FTD software allows an unauthenticated remote attacker to exhaust limited Direct Memory Access (DMA) memory by sending a sustained high rate of malicious traffic, causing the device to reload and result in a denial of service.

MitigationApply Cisco-provided software updates/patches for ASA and FTD. As a workaround, implement rate limiting or traffic filtering on upstream devices to reduce the impact of sustained high-volume attacks.

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 Threat DefenseApplication
Affected:= 6.0
Secure Firewall Threat DefenseApplication
Affected:= 6.0.1= 6.1.0= 6.2.0= 6.2.2= 6.2.3
Adaptive Security Appliance SoftwareOperating system
Affected:= 9.3= 9.4= 9.5= 9.6= 9.6\(43\)= 9.7= 9.8= 9.9= 9.9\(28\)

CVSS 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
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

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 checks

Work through these to decide whether this CVE applies to you.

  1. Check Cisco ASA software version
    Log into the ASA CLI and run the command: `show version` - look for the software version number in the output
    Affected if The version shown is 9.3, 9.4, 9.5, 9.6, 9.6(43), 9.7, 9.8, 9.9, or 9.9(28)
  2. Check Cisco FTD software version
    Log into the FTD CLI (via SSH or console) and run: `show version` or access Firepower Management Center to view the device version
    Affected if The version shown is 6.0, 6.0.1, 6.1.0, 6.2.0, 6.2.2, or 6.2.3
  3. Verify network exposure to untrusted traffic
    Review the ASA/FTD interface configurations to determine if the device accepts traffic from untrusted networks (such as the internet) on any interface
    Affected if The device has interfaces directly exposed to untrusted/external networks and processes inbound traffic
  4. Check for active VPN or SSL decryption configurations
    Review the device configuration for any active site-to-site VPN, remote-access VPN, or SSL decryption policies using the `show run` command
    Affected if VPN termination or SSL decryption features are enabled, as these utilize the cryptographic hardware accelerator

You are affected if your device runs an affected ASA version (9.3-9.9.x) or FTD version (6.0-6.2.3) and is exposed to untrusted network traffic that can trigger the cryptographic hardware accelerator.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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 data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply Cisco-provided software updates/patches for ASA and FTD. As a workaround, implement rate limiting or traffic filtering on upstream devices to reduce the impact of sustained high-volume attacks.

Fix this in Firepower Threat Defense Scoped from the published advisory
  • Consultation2.0 h
  • Implementation3.0 h
  • Testing2.0 h
  • Review / QA1.0 h
8.0 hours of engineering $1,420
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2018-15383 in production — separate from our analysis above.

No notes yet

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What this is

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.

What belongs here
  • 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
  • No spam, self-promotion, credentials, or personal data