# What is CVE-2019-1866?

> CVE-2019-1866 is a low-severity flaw (CVSS 3.7) in Webex Business Suite 39 from Cisco, published on 13 April 2020. 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 0.3%. If you run an affected version, plan in the vendor’s fix.

Canonical page: https://www.precursorintelligence.com/what-is/cve-2019-1866

## At a glance

- **Verdict:** Plan it in. No sign of exploitation and a low forecast. Patch it in your normal update cycle.
- **Precursor Intelligence risk score:** 22 out of 100 (Low); action: Monitor. Kept up to date as the evidence changes.
- **Severity:** Low (CVSS 3.7 out of 10)
- **Known to be exploited:** No, not on the list of flaws known to be exploited today
- **Chance of use in the next 30 days:** 0.3% (latest exploit-likelihood forecast)
- **Published:** 13 April 2020
- **Record last updated:** 13 April 2020
- **Main product:** Webex Business Suite 39 from Cisco
- **Affected products:** 1

## What is CVE-2019-1866? 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 change some data.

### The official description

Cisco Webex Business Suite before 39.1.0 contains a vulnerability that could allow an unauthenticated, remote attacker to affect the integrity of the application. The vulnerability is due to improper validation of host header values. An attacker with a privileged network position, either a man-in-the-middle or by intercepting wireless network traffic, could exploit this vulnerability to manipulate header values sent by a client to the affected application. The attacker could cause the application to use input from the header to redirect a user from the Cisco Webex Meetings Online site to an arbitrary site of the attacker's choosing.

### What kind of flaw is it?

- CWE-284: Improper Access Control
- CWE-345: Insufficient Verification of Data Authenticity

### How an attack on it works

- Where an attacker can be: Anywhere on the internet
- How hard it is to pull off: Hard: conditions must line up
- Login needed first: No login needed
- Does someone have to click: No, nobody has to do anything
- What an attacker gets: Can change some data

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

## Is CVE-2019-1866 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 0.3%. That can change at any time, which is why we keep watching.

Exploit likelihood over the last 7 days: 0.3%, 0.3%, 0.3%, 0.3%, 0.3%, 0.3%, 0.3%.

### Timeline

- 13 April 2020: Published

### How Precursor Intelligence ranks it

CVE-2019-1866 scores **22 out of 100 (Low)**, with the action "Monitor".

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-2019-1866?

The published record lists 1 product. Versions are as published: "before 39.1.0" means every version up to, but not including, 39.1.0.

- [Webex Business Suite 39](https://www.precursorintelligence.com/product/cisco/webex_business_suite_39) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Application): before 39.1.0

## How do I fix CVE-2019-1866?

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. **Keep an eye on it.** Track 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

- [quickview.cloudapps.cisco.com](https://quickview.cloudapps.cisco.com/quickview/bug/CSCvm98833) (Vendor advisory)

## Questions

### What is CVE-2019-1866?

CVE-2019-1866 is a low-severity flaw in Webex Business Suite 39 from Cisco, published on 13 April 2020. It can be attacked from anywhere on the internet without logging in, and nobody has to click anything. If it works, the attacker can change some data.

### How serious is CVE-2019-1866?

It scores 3.7 out of 10 on the CVSS severity scale, which is low. Our risk score for CVE-2019-1866 is 22 out of 100, which is Low. Its action is "Monitor". No sign of exploitation and a low forecast. Patch it in your normal update cycle.

### Is CVE-2019-1866 being exploited?

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 0.3%. That can change at any time, which is why we keep watching.

### Which versions does CVE-2019-1866 affect?

For Webex Business Suite 39 from Cisco: before 39.1.0.

### How do I fix CVE-2019-1866?

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.

## Does CVE-2019-1866 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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