# What is CVE-2023-20234?

> CVE-2023-20234 is a medium-severity flaw (CVSS 6.0) in Firepower Extensible Operating System from Cisco, published on 23 August 2023. 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 0.2%. If you run an affected version, plan in the vendor’s fix.

Canonical page: https://www.precursorintelligence.com/what-is/cve-2023-20234

## 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:** 18 out of 100 (Info); action: Track. Kept up to date as the evidence changes.
- **Severity:** Medium (CVSS 6.0 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:** 0.2% (latest exploit-likelihood forecast)
- **Published:** 23 August 2023
- **Record last updated:** 25 January 2024
- **Main product:** Firepower Extensible Operating System from Cisco
- **Affected products:** 43

## What is CVE-2023-20234? In plain terms

An attacker has to be already on the device with an administrator account, and nobody has to click anything. If it works, the attacker can change data and take it offline.

### The official description

A vulnerability in the CLI of Cisco FXOS Software could allow an authenticated, local attacker to create a file or overwrite any file on the filesystem of an affected device, including system files.
 The vulnerability occurs because there is no validation of parameters when a specific CLI command is used. An attacker could exploit this vulnerability by authenticating to an affected device and using the command at the CLI. A successful exploit could allow the attacker to overwrite any file on the disk of the affected device, including system files. The attacker must have valid administrative credentials on the affected device to exploit this vulnerability.

### What kind of flaw is it?

- CWE-732: Incorrect Permission Assignment for Critical Resource
- CWE-73: External Control of File Name or Path

### How an attack on it works

- Where an attacker can be: Already on the device
- How hard it is to pull off: Easy: no special conditions
- Login needed first: An administrator account
- Does someone have to click: No, nobody has to do anything
- What an attacker gets: Can change data and take it offline

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

## Is CVE-2023-20234 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 0.2%. That can change at any time, which is why we keep watching.

Exploit likelihood over the last 7 days: 0.2%, 0.2%, 0.2%, 0.2%, 0.2%, 0.2%, 0.2%.

### Timeline

- 23 August 2023: Published
- 25 January 2024: Record last updated

### How Precursor Intelligence ranks it

CVE-2023-20234 scores **18 out of 100 (Info)**, with the action "Track".

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-2023-20234?

The published record lists 43 products.

- [Firepower Extensible Operating System](https://www.precursorintelligence.com/product/cisco/firepower_extensible_operating_system) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Application): version not specified
- [Firepower 1000](https://www.precursorintelligence.com/product/cisco/firepower_1000) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Firepower 1010](https://www.precursorintelligence.com/product/cisco/firepower_1010) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Firepower 1020](https://www.precursorintelligence.com/product/cisco/firepower_1020) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Firepower 1030](https://www.precursorintelligence.com/product/cisco/firepower_1030) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Firepower 1040](https://www.precursorintelligence.com/product/cisco/firepower_1040) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Firepower 2100](https://www.precursorintelligence.com/product/cisco/firepower_2100) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Firepower 2110](https://www.precursorintelligence.com/product/cisco/firepower_2110) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Firepower 2120](https://www.precursorintelligence.com/product/cisco/firepower_2120) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Firepower 2130](https://www.precursorintelligence.com/product/cisco/firepower_2130) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Firepower 2140](https://www.precursorintelligence.com/product/cisco/firepower_2140) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Firepower 4100](https://www.precursorintelligence.com/product/cisco/firepower_4100) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Firepower 4110](https://www.precursorintelligence.com/product/cisco/firepower_4110) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Firepower 4110 Next-Generation Firewall](https://www.precursorintelligence.com/product/cisco/firepower_4110_next-generation_firewall) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Firepower 4112](https://www.precursorintelligence.com/product/cisco/firepower_4112) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Firepower 4115](https://www.precursorintelligence.com/product/cisco/firepower_4115) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Firepower 4120](https://www.precursorintelligence.com/product/cisco/firepower_4120) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Firepower 4120 Next-Generation Firewall](https://www.precursorintelligence.com/product/cisco/firepower_4120_next-generation_firewall) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Firepower 4125](https://www.precursorintelligence.com/product/cisco/firepower_4125) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Firepower 4140](https://www.precursorintelligence.com/product/cisco/firepower_4140) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Firepower 4140 Next-Generation Firewall](https://www.precursorintelligence.com/product/cisco/firepower_4140_next-generation_firewall) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Firepower 4145](https://www.precursorintelligence.com/product/cisco/firepower_4145) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Firepower 4150](https://www.precursorintelligence.com/product/cisco/firepower_4150) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Firepower 4150 Next-Generation Firewall](https://www.precursorintelligence.com/product/cisco/firepower_4150_next-generation_firewall) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Firepower 9300](https://www.precursorintelligence.com/product/cisco/firepower_9300) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Firepower 9300 Security Appliance](https://www.precursorintelligence.com/product/cisco/firepower_9300_security_appliance) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Firepower 9300 Sm-24](https://www.precursorintelligence.com/product/cisco/firepower_9300_sm-24) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Firepower 9300 Sm-36](https://www.precursorintelligence.com/product/cisco/firepower_9300_sm-36) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Firepower 9300 Sm-40](https://www.precursorintelligence.com/product/cisco/firepower_9300_sm-40) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Firepower 9300 Sm-44](https://www.precursorintelligence.com/product/cisco/firepower_9300_sm-44) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Firepower 9300 Sm-44 X 3](https://www.precursorintelligence.com/product/cisco/firepower_9300_sm-44_x_3) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Firepower 9300 Sm-48](https://www.precursorintelligence.com/product/cisco/firepower_9300_sm-48) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Firepower 9300 Sm-56](https://www.precursorintelligence.com/product/cisco/firepower_9300_sm-56) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Firepower 9300 Sm-56 X 3](https://www.precursorintelligence.com/product/cisco/firepower_9300_sm-56_x_3) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Firepower 9300 with 1 Sm-24 Module](https://www.precursorintelligence.com/product/cisco/firepower_9300_with_1_sm-24_module) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Firepower 9300 with 1 Sm-36 Module](https://www.precursorintelligence.com/product/cisco/firepower_9300_with_1_sm-36_module) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Firepower 9300 with 1 Sm-44 Module](https://www.precursorintelligence.com/product/cisco/firepower_9300_with_1_sm-44_module) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Firepower 9300 with 3 Sm-44 Module](https://www.precursorintelligence.com/product/cisco/firepower_9300_with_3_sm-44_module) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Secure Firewall 3105](https://www.precursorintelligence.com/product/cisco/secure_firewall_3105) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Secure Firewall 3110](https://www.precursorintelligence.com/product/cisco/secure_firewall_3110) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Secure Firewall 3120](https://www.precursorintelligence.com/product/cisco/secure_firewall_3120) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Secure Firewall 3130](https://www.precursorintelligence.com/product/cisco/secure_firewall_3130) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Secure Firewall 3140](https://www.precursorintelligence.com/product/cisco/secure_firewall_3140) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified

## How do I fix CVE-2023-20234?

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

- [sec.cloudapps.cisco.com](https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-fxos-arbitrary-file-BLk6YupL) (Vendor advisory)

## Questions

### What is CVE-2023-20234?

CVE-2023-20234 is a medium-severity flaw in Firepower Extensible Operating System from Cisco, published on 23 August 2023. An attacker has to be already on the device with an administrator account, and nobody has to click anything. If it works, the attacker can change data and take it offline.

### How serious is CVE-2023-20234?

It scores 6.0 out of 10 on the CVSS severity scale, which is medium. Our risk score for CVE-2023-20234 is 18 out of 100, which is Info. Its action is "Track". No sign of exploitation and a low forecast. Patch it in your normal update cycle.

### Is CVE-2023-20234 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 0.2%. That can change at any time, which is why we keep watching.

### Which versions does CVE-2023-20234 affect?

For Firepower Extensible Operating System from Cisco: version not specified. The record lists 43 products in all, each with its versions, under "Who is affected" on this page.

### How do I fix CVE-2023-20234?

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-2023-20234 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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