# What is CVE-2022-20943?

> CVE-2022-20943 is a medium-severity flaw (CVSS 5.8) in Firepower Threat Defense from Cisco, published on 15 November 2022. 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 1.0%. If you run an affected version, plan in the vendor’s fix.

Canonical page: https://www.precursorintelligence.com/what-is/cve-2022-20943

## 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:** 29 out of 100 (Low); action: Monitor. Kept up to date as the evidence changes.
- **Severity:** Medium (CVSS 5.8 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:** 1.0% (latest exploit-likelihood forecast)
- **Published:** 15 November 2022
- **Record last updated:** 25 January 2024
- **Main product:** Firepower Threat Defense from Cisco
- **Affected products:** 3

## What is CVE-2022-20943? 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 slow it down.

### The official description

Multiple vulnerabilities in the Server Message Block Version 2 (SMB2) processor of the Snort detection engine on multiple Cisco products could allow an unauthenticated, remote attacker to bypass the configured policies or cause a denial of service (DoS) condition on an affected device.
 These vulnerabilities are due to improper management of system resources when the Snort detection engine is processing SMB2 traffic. An attacker could exploit these vulnerabilities by sending a high rate of certain types of SMB2 packets through an affected device. A successful exploit could allow the attacker to trigger a reload of the Snort process, resulting in a DoS condition.
 Note: When the snort preserve-connection option is enabled for the Snort detection engine, a successful exploit could also allow the attacker to bypass the configured policies and deliver a malicious payload to the protected network. The snort preserve-connection setting is enabled by default. See the Details ["#details"] section of this advisory for more information.
 Note: Only products that have Snort 3 configured are affected. Products that are configured with Snort 2 are not affected.

### What kind of flaw is it?

- CWE-244: Improper Clearing of Heap Memory Before Release ('Heap Inspection')

### 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 slow it down

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

## Is CVE-2022-20943 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 1.0%. That can change at any time, which is why we keep watching.

Exploit likelihood over the last 7 days: 0.9%, 0.9%, 0.9%, 0.9%, 0.9%, 1.0%, 1.0%.

### Timeline

- 15 November 2022: Published
- 25 January 2024: Record last updated

### How Precursor Intelligence ranks it

CVE-2022-20943 scores **29 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-2022-20943?

The published record lists 3 products. Versions are as published: "before 16.6.7" means every version up to, but not including, 16.6.7.

- [Firepower Threat Defense](https://www.precursorintelligence.com/product/cisco/firepower_threat_defense) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Application): 7.0.0, 7.0.0.1, 7.0.1, 7.0.1.1
- [Cyber Vision](https://www.precursorintelligence.com/product/cisco/cyber_vision) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Application): 3.0.0, 3.0.1, 3.0.2, 3.0.3, 3.0.5, 3.0.6, 3.1.0, 3.1.1, 3.1.2, 3.2.0, 3.2.1, 3.2.2, 3.2.3, 3.2.4, 4.0.0, 4.0.1, 4.0.2, 4.0.3, 4.1.0, 4.1.1
- [Meraki MX Security Appliance Firmware](https://www.precursorintelligence.com/product/cisco/meraki_mx_security_appliance_firmware) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Operating system): before 16.6.7, 17.0 to before 17.11.1, 18.0 to before 18.1.3

## How do I fix CVE-2022-20943?

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 latest update from the vendor. The references list where the vendor has published details.
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

- [sec.cloudapps.cisco.com](https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-snort-smb-3nfhJtr)

## Questions

### What is CVE-2022-20943?

CVE-2022-20943 is a medium-severity flaw in Firepower Threat Defense from Cisco, published on 15 November 2022. It can be attacked from anywhere on the internet without logging in, and nobody has to click anything. If it works, the attacker can slow it down.

### How serious is CVE-2022-20943?

It scores 5.8 out of 10 on the CVSS severity scale, which is medium. Our risk score for CVE-2022-20943 is 29 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-2022-20943 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 1.0%. That can change at any time, which is why we keep watching.

### Which versions does CVE-2022-20943 affect?

For Firepower Threat Defense from Cisco: 7.0.0, 7.0.0.1, 7.0.1, 7.0.1.1. The record lists 3 products in all, each with its versions, under "Who is affected" on this page.

### How do I fix CVE-2022-20943?

Install the update the vendor names in its advisory. If you can't patch today, follow the vendor's mitigation and limit who can reach the affected system from the internet.

## Does CVE-2022-20943 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.
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