Sign inStart freeBook a demo

What is CVE-2018-0101?A critical-severity flaw in Firepower Threat Defense, explained.

Critical severity2 affected products
The short answer

CVE-2018-0101 is a critical-severity flaw (CVSS 10.0) in Firepower Threat Defense from Cisco, published on 29 January 2018. It is not on the list of flaws known to be exploited today. The latest forecast puts its chance of use in the next 30 days at 87%. If you run an affected version, plan in the vendor’s fix.

Check if it affects you →How to fix it

Published 29 January 2018. Record last updated 15 August 2023. We keep this page's data up to date.

What it does

What is CVE-2018-0101? 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 read data, change data and take it offline.

The official description

A vulnerability in the Secure Sockets Layer (SSL) VPN functionality of the Cisco Adaptive Security Appliance (ASA) Software could allow an unauthenticated, remote attacker to cause a reload of the affected system or to remotely execute code. The vulnerability is due to an attempt to double free a region of memory when the webvpn feature is enabled on the Cisco ASA device. An attacker could exploit this vulnerability by sending multiple, crafted XML packets to a webvpn-configured interface on the affected system. An exploit could allow the attacker to execute arbitrary code and obtain full control of the system, or cause a reload of the affected device. This vulnerability affects Cisco ASA Software that is running on the following Cisco products: 3000 Series Industrial Security Appliance (ISA), 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, ASA 1000V Cloud Firewall, Adaptive Security Virtual Appliance (ASAv), Firepower 2100 Series Security Appliance, Firepower 4110 Security Appliance, Firepower 9300 ASA Security Module, Firepower Threat Defense Software (FTD). Cisco Bug IDs: CSCvg35618.

What kind of flaw is it?

  • CWE-415Double Free
CVSS 3.0 scoreCritical · 10.0

How an attack on it works

Read straight from its severity rating, translated out of the shorthand.

  • Where an attacker can beAnywhere on the internet
  • How hard it is to pull offEasy: no special conditions
  • Login needed firstNo login needed
  • Does someone have to clickNo, nobody has to do anything
  • What an attacker getsCan read data, change data and take it offline

Severity vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

Exploitation

Is CVE-2018-0101 being exploited? Not that we know of.

It is not on the list of flaws known to be exploited today. The latest forecast puts the chance of it being used in the next 30 days at 87%. That can change at any time, which is why we keep watching.

Known to be exploitedNoNot on the list of exploited flaws today
Chance of use in the next 30 days87%Its EPSS score, from the latest forecast

Timeline

  1. Published
  2. Record last updated
  3. Exploit likelihood fell
  4. Exploit likelihood jumped
How Precursor Intelligence ranks it
83out of 100High

CVE-2018-0101 scores 83. Action: Patch now.

We keep the score of every published flaw up to date as the evidence changes. Four things go into the score, and evidence that criminals are actually using it counts most. In order:

  • Evidence it is being exploitedBiggest factor
  • How severe it isStrong factor
  • How widely exposed it isSmaller factor
  • Threat activity around itSmaller factor

85 and above is Critical. Anything confirmed as exploited is always marked for an emergency patch, whatever its score.

When CVE-2018-0101 matches software you track, it lands in your list with its score and the reasons behind it.

See your own ranked list →
Affected products

Who is affected by CVE-2018-0101? 2 products.

The published record lists 2 products from 1 vendor. Versions are shown as published: "before 9.1.7.23" means every version up to, but not including, 9.1.7.23. If you run one of these, check your version, then go to the fix below.

Remediation

How do I fix CVE-2018-0101? Four steps.

  1. Check whether you run itCompare 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 fixInstall the update named in the vendor’s advisory. We’ve put the advisory first in the list.
  3. If you can’t patch todayFollow any mitigation the vendor publishes, and limit who can reach the affected system from the internet until the update is in.
  4. Keep an eye on itTrack the product and we tell you as soon as we spot this flaw on the list of exploited flaws, or a jump in its exploit likelihood.

References

6 links
Precursor Intelligence

Does CVE-2018-0101 affect you? We'll keep checking.

Looking flaws up one at a time doesn't scale. Tell us what you run once, and we tell you which flaws matter to you, in what order, and keep watching for new ones.

  1. Tell us what you runPick your software from a list, or let us work it out from your website.
  2. We match it to every flawOver 400,000 published flaws, checked against your list.
  3. Ranked by real-world riskA 0 to 100 score, led by evidence criminals are using it.
  4. Told as soon as we knowAn alert by email, in the app or by webhook to your own tools.
Start free →Book a demo

Free plan, no card needed. Nothing to install.

FAQ

Common questions, answered plainly.

Something else? Talk to the team →

CVE-2018-0101 is a critical-severity flaw in Firepower Threat Defense from Cisco, published on 29 January 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 read data, change data and take it offline.

It scores 10.0 out of 10 on the CVSS severity scale, which is critical. Our risk score for CVE-2018-0101 is 83 out of 100, which is High. Its action is "Patch now". Not confirmed as exploited yet, but serious or likely enough that it should not wait for a quiet month.

It is not on the list of flaws known to be exploited today. The latest forecast puts the chance of it being used in the next 30 days at 87%. That can change at any time, which is why we keep watching.

For Firepower Threat Defense from Cisco: 6.0.0, 6.0.1, 6.1.0, 6.2.0, 6.2.1, 6.2.2. The record lists 2 products in all, each with its versions, under "Who is affected" on this page.

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.

Keep exploring