# What is CVE-2018-0296?

> CVE-2018-0296 is a high-severity flaw (CVSS 7.5) in Firepower Threat Defense from Cisco, published on 7 June 2018. It is on the list of flaws known to be exploited, so criminals are already using it. The latest forecast puts its chance of use in the next 30 days at over 99%. If you run an affected version, patch it first.

Canonical page: https://www.precursorintelligence.com/what-is/cve-2018-0296

## At a glance

- **Verdict:** Fix this now. Attackers are using this flaw today. If you run an affected version, it goes to the top of your list.
- **Precursor Intelligence risk score:** 80 out of 100 (High); action: Emergency patch. Kept up to date as the evidence changes.
- **Severity:** High (CVSS 7.5 out of 10)
- **Known to be exploited:** Yes, it is on the government list of flaws known to be exploited
- **Chance of use in the next 30 days:** over 99% (latest exploit-likelihood forecast)
- **Published:** 7 June 2018
- **Record last updated:** 28 October 2025
- **Main product:** Firepower Threat Defense from Cisco
- **Affected products:** 2

## What is CVE-2018-0296? In plain terms

It can be attacked from anywhere on the internet without logging in, and nobody has to click anything. If it works, the attacker can take it offline.

### The official description

A vulnerability in the web interface of the Cisco Adaptive Security Appliance (ASA) could allow an unauthenticated, remote attacker to cause an affected device to reload unexpectedly, resulting in a denial of service (DoS) condition. It is also possible on certain software releases that the ASA will not reload, but an attacker could view sensitive system information without authentication by using directory traversal techniques. The vulnerability is due to lack of proper input validation of the HTTP URL. An attacker could exploit this vulnerability by sending a crafted HTTP request to an affected device. An exploit could allow the attacker to cause a DoS condition or unauthenticated disclosure of information. This vulnerability applies to IPv4 and IPv6 HTTP traffic. This vulnerability affects Cisco ASA Software and Cisco Firepower Threat Defense (FTD) Software that is running on the following Cisco products: 3000 Series Industrial Security Appliance (ISA), ASA 1000V Cloud Firewall, ASA 5500 Series Adaptive Security Appliances, ASA 5500-X Series Next-Generation Firewalls, ASA Services Module for Cisco Catalyst 6500 Series Switches and Cisco 7600 Series Routers, Adaptive Security Virtual Appliance (ASAv), Firepower 2100 Series Security Appliance, Firepower 4100 Series Security Appliance, Firepower 9300 ASA Security Module, FTD Virtual (FTDv). Cisco Bug IDs: CSCvi16029.

### What kind of flaw is it?

- CWE-20: Improper Input Validation
- CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

### How an attack on it works

- Where an attacker can be: Anywhere on the internet
- How hard it is to pull off: Easy: no special conditions
- Login needed first: No login needed
- Does someone have to click: No, nobody has to do anything
- What an attacker gets: Can take it offline

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

## Is CVE-2018-0296 being exploited? Yes

Attackers are already using it. It is on the government list of flaws known to be exploited, and the latest forecast puts the chance of it being used in the next 30 days at over 99%.

Exploit likelihood over the last 7 days: >99%, >99%, >99%, >99%, >99%, >99%, >99%.

### Timeline

- 7 June 2018: Published
- 28 October 2025: Record last updated

### How Precursor Intelligence ranks it

CVE-2018-0296 scores **80 out of 100 (High)**, with the action "Emergency patch".

Every published flaw gets a risk score from 0 to 100, kept up to date as the evidence changes. Four things go into the score, from the one that counts most to the ones that count less:

- Evidence it is being exploited: biggest factor
- How severe it is: strong factor
- How widely exposed it is: smaller factor
- Threat activity around it: smaller factor

85 and above is Critical. Anything confirmed as exploited is always marked for an emergency patch, whatever its score. When this flaw matches software you track, it lands in your list with its score and the reasons behind it.

## Who is affected by CVE-2018-0296?

The published record lists 2 products. Versions are as published: "6.0 to before 6.1.0" means from 6.0 up to, but not including, 6.1.0.

- [Firepower Threat Defense](https://www.precursorintelligence.com/product/cisco/firepower_threat_defense) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Application): 6.0 to before 6.1.0, 6.2.1 to before 6.2.2.3, 6.2.3, 6.2.3.1, 6.2.3-85.02, 6.2.3-851
- [Adaptive Security Appliance Software](https://www.precursorintelligence.com/product/cisco/adaptive_security_appliance_software) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Application): 8.1(2.5), 9.1 to before 9.1.7.29, 9.2 to before 9.2.4.33, 9.3 to before 9.4.4.18, 9.5 to before 9.6.4.8, 9.7 to before 9.7.1.24, 9.8 to before 9.8.2.28, 9.9 to before 9.9.2.1

## How do I fix CVE-2018-0296?

1. **Check whether you run it.** Compare your versions with the affected products above. Not sure what you run? Precursor Intelligence can work it out from your public website, or you can pick it from a list.
2. **Apply the vendor’s fix.** Install the update named in the vendor’s advisory. We’ve put the advisory first in the list.
3. **If you can’t patch today.** Follow any mitigation the vendor publishes, and limit who can reach the affected system from the internet until the update is in.
4. **Check it wasn’t used before you patched.** Because criminals are already using this flaw, look for signs of a break-in on affected systems using the vendor’s guidance.

### References

- [tools.cisco.com](https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20180606-asaftd) (Vendor advisory)
- [packetstormsecurity.com](http://packetstormsecurity.com/files/154017/Cisco-Adaptive-Security-Appliance-Path-Traversal.html) (Exploit, Third-party advisory, Vulnerability database)
- [securityfocus.com](http://www.securityfocus.com/bid/104612) (Third-party advisory, Vulnerability database)
- [securitytracker.com](http://www.securitytracker.com/id/1041076) (Third-party advisory, Vulnerability database)
- [ics-cert.us-cert.gov](https://ics-cert.us-cert.gov/advisories/ICSA-18-184-01) (Third-party advisory, Government resource)
- [exploit-db.com](https://www.exploit-db.com/exploits/44956/) (Exploit, Third-party advisory, Vulnerability database)
- [cisa.gov](https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2018-0296) (Government resource)

## Questions

### What is CVE-2018-0296?

CVE-2018-0296 is a high-severity flaw in Firepower Threat Defense from Cisco, published on 7 June 2018. It can be attacked from anywhere on the internet without logging in, and nobody has to click anything. If it works, the attacker can take it offline.

### How serious is CVE-2018-0296?

It scores 7.5 out of 10 on the CVSS severity scale, which is high. Our risk score for CVE-2018-0296 is 80 out of 100, which is High. Its action is "Emergency patch". Attackers are using this flaw today. If you run an affected version, it goes to the top of your list.

### Is CVE-2018-0296 being exploited?

Attackers are already using it. It is on the government list of flaws known to be exploited, and the latest forecast puts the chance of it being used in the next 30 days at over 99%.

### Which versions does CVE-2018-0296 affect?

For Firepower Threat Defense from Cisco: 6.0 to before 6.1.0, 6.2.1 to before 6.2.2.3, 6.2.3, 6.2.3.1, 6.2.3-85.02, 6.2.3-851. The record lists 2 products in all, each with its versions, under "Who is affected" on this page.

### How do I fix CVE-2018-0296?

Install the update the vendor names in its advisory, linked first under "How do I fix" on this page. If you can't patch today, follow the vendor's mitigation and limit who can reach the affected system from the internet. Because criminals are already using it, also check affected systems for signs of a break-in.

## Does CVE-2018-0296 affect you?

Precursor Intelligence keeps checking for you:

- **Tell us what you run.** Pick your software from a list, or let us work it out from your website.
- **We match it to every flaw.** Over 400,000 published flaws, checked against your list.
- **Ranked by real-world risk.** Every flaw gets a 0 to 100 risk score, kept up to date, led by evidence criminals are using it.
- **Told as soon as we know.** An alert by email, in the app or by webhook to your own tools.

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