# What is CVE-2021-3453?

> CVE-2021-3453 is a medium-severity flaw (CVSS 4.6) in Thinkpad Helix Firmware from Lenovo, published on 16 July 2021. 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-2021-3453

## 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:** 21 out of 100 (Low); action: Monitor. Kept up to date as the evidence changes.
- **Severity:** Medium (CVSS 4.6 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:** 16 July 2021
- **Record last updated:** 30 July 2021
- **Main product:** Thinkpad Helix Firmware from Lenovo
- **Affected products:** 42

## What is CVE-2021-3453? In plain terms

An attacker has to be physically at the device without logging in, and nobody has to click anything. If it works, the attacker can change data.

### The official description

Some Lenovo Notebook, ThinkPad, and Lenovo Desktop systems have BIOS modules unprotected by Intel Boot Guard that could allow an attacker with physical access the ability to write to the SPI flash storage.

### What kind of flaw is it?

- CWE-693: Protection Mechanism Failure

### How an attack on it works

- Where an attacker can be: Physically at the device
- 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 change data

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

## Is CVE-2021-3453 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

- 16 July 2021: Published
- 30 July 2021: Record last updated

### How Precursor Intelligence ranks it

CVE-2021-3453 scores **21 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-2021-3453?

The published record lists 42 products. Versions are as published: "before 2021-09-30" means every version up to, but not including, 2021-09-30.

- [Thinkpad Helix Firmware](https://www.precursorintelligence.com/product/lenovo/thinkpad_helix_firmware) by [Lenovo](https://www.precursorintelligence.com/vendors/lenovo) (Operating system): n17etb4w
- [730s-13iml](https://www.precursorintelligence.com/product/lenovo/730s-13iml) by [Lenovo](https://www.precursorintelligence.com/vendors/lenovo) (Hardware): version not specified
- [730s-13iml Firmware](https://www.precursorintelligence.com/product/lenovo/730s-13iml_firmware) by [Lenovo](https://www.precursorintelligence.com/vendors/lenovo) (Operating system): version not specified
- [Ideacentre Aio 5-24imb05](https://www.precursorintelligence.com/product/lenovo/ideacentre_aio_5-24imb05) by [Lenovo](https://www.precursorintelligence.com/vendors/lenovo) (Hardware): version not specified
- [Ideacentre Aio 5-24imb05 Firmware](https://www.precursorintelligence.com/product/lenovo/ideacentre_aio_5-24imb05_firmware) by [Lenovo](https://www.precursorintelligence.com/vendors/lenovo) (Operating system): before 2021-09-30
- [Ideacentre Aio 5-74imb05](https://www.precursorintelligence.com/product/lenovo/ideacentre_aio_5-74imb05) by [Lenovo](https://www.precursorintelligence.com/vendors/lenovo) (Hardware): version not specified
- [Ideacentre Aio 5-74imb05 Firmware](https://www.precursorintelligence.com/product/lenovo/ideacentre_aio_5-74imb05_firmware) by [Lenovo](https://www.precursorintelligence.com/vendors/lenovo) (Operating system): before 2021-09-30
- [Ideapad 1-11igl05](https://www.precursorintelligence.com/product/lenovo/ideapad_1-11igl05) by [Lenovo](https://www.precursorintelligence.com/vendors/lenovo) (Hardware): version not specified
- [Ideapad 1-11igl05 Firmware](https://www.precursorintelligence.com/product/lenovo/ideapad_1-11igl05_firmware) by [Lenovo](https://www.precursorintelligence.com/vendors/lenovo) (Operating system): version not specified
- [Ideapad 1-14igl05](https://www.precursorintelligence.com/product/lenovo/ideapad_1-14igl05) by [Lenovo](https://www.precursorintelligence.com/vendors/lenovo) (Hardware): version not specified
- [Ideapad 1-14igl05 Firmware](https://www.precursorintelligence.com/product/lenovo/ideapad_1-14igl05_firmware) by [Lenovo](https://www.precursorintelligence.com/vendors/lenovo) (Operating system): version not specified
- [Ideapad S940-14iil](https://www.precursorintelligence.com/product/lenovo/ideapad_s940-14iil) by [Lenovo](https://www.precursorintelligence.com/vendors/lenovo) (Hardware): version not specified
- [Ideapad S940-14iil Firmware](https://www.precursorintelligence.com/product/lenovo/ideapad_s940-14iil_firmware) by [Lenovo](https://www.precursorintelligence.com/vendors/lenovo) (Operating system): version not specified
- [Ideapad S940-14iwl](https://www.precursorintelligence.com/product/lenovo/ideapad_s940-14iwl) by [Lenovo](https://www.precursorintelligence.com/vendors/lenovo) (Hardware): version not specified
- [Ideapad S940-14iwl Firmware](https://www.precursorintelligence.com/product/lenovo/ideapad_s940-14iwl_firmware) by [Lenovo](https://www.precursorintelligence.com/vendors/lenovo) (Operating system): version not specified
- [Ideapad Slim 1-11ast-05](https://www.precursorintelligence.com/product/lenovo/ideapad_slim_1-11ast-05) by [Lenovo](https://www.precursorintelligence.com/vendors/lenovo) (Hardware): version not specified
- [Ideapad Slim 1-11ast-05 Firmware](https://www.precursorintelligence.com/product/lenovo/ideapad_slim_1-11ast-05_firmware) by [Lenovo](https://www.precursorintelligence.com/vendors/lenovo) (Operating system): version not specified
- [Ideapad Slim 1-14ast-05](https://www.precursorintelligence.com/product/lenovo/ideapad_slim_1-14ast-05) by [Lenovo](https://www.precursorintelligence.com/vendors/lenovo) (Hardware): version not specified
- [Ideapad Slim 1-14ast-05 Firmware](https://www.precursorintelligence.com/product/lenovo/ideapad_slim_1-14ast-05_firmware) by [Lenovo](https://www.precursorintelligence.com/vendors/lenovo) (Operating system): version not specified
- [Thinkpad Helix](https://www.precursorintelligence.com/product/lenovo/thinkpad_helix) by [Lenovo](https://www.precursorintelligence.com/vendors/lenovo) (Hardware): version not specified
- [Thinkpad T550](https://www.precursorintelligence.com/product/lenovo/thinkpad_t550) by [Lenovo](https://www.precursorintelligence.com/vendors/lenovo) (Hardware): version not specified
- [Thinkpad T550 Firmware](https://www.precursorintelligence.com/product/lenovo/thinkpad_t550_firmware) by [Lenovo](https://www.precursorintelligence.com/vendors/lenovo) (Operating system): n11et53w
- [Thinkpad W550s](https://www.precursorintelligence.com/product/lenovo/thinkpad_w550s) by [Lenovo](https://www.precursorintelligence.com/vendors/lenovo) (Hardware): version not specified
- [Thinkpad W550s Firmware](https://www.precursorintelligence.com/product/lenovo/thinkpad_w550s_firmware) by [Lenovo](https://www.precursorintelligence.com/vendors/lenovo) (Operating system): n11et53w
- [Thinkpad X1 Carbon 3rd Gen](https://www.precursorintelligence.com/product/lenovo/thinkpad_x1_carbon_3rd_gen) by [Lenovo](https://www.precursorintelligence.com/vendors/lenovo) (Hardware): version not specified
- [Thinkpad X1 Carbon 3rd Gen Firmware](https://www.precursorintelligence.com/product/lenovo/thinkpad_x1_carbon_3rd_gen_firmware) by [Lenovo](https://www.precursorintelligence.com/vendors/lenovo) (Operating system): n14et55w
- [Thinkpad X250](https://www.precursorintelligence.com/product/lenovo/thinkpad_x250) by [Lenovo](https://www.precursorintelligence.com/vendors/lenovo) (Hardware): version not specified
- [Thinkpad X250 Firmware](https://www.precursorintelligence.com/product/lenovo/thinkpad_x250_firmware) by [Lenovo](https://www.precursorintelligence.com/vendors/lenovo) (Operating system): n10et62w
- [Thinkpad Yoga 15](https://www.precursorintelligence.com/product/lenovo/thinkpad_yoga_15) by [Lenovo](https://www.precursorintelligence.com/vendors/lenovo) (Hardware): version not specified
- [Thinkpad Yoga 15 Firmware](https://www.precursorintelligence.com/product/lenovo/thinkpad_yoga_15_firmware) by [Lenovo](https://www.precursorintelligence.com/vendors/lenovo) (Operating system): n19et65w
- [V130-15igm](https://www.precursorintelligence.com/product/lenovo/v130-15igm) by [Lenovo](https://www.precursorintelligence.com/vendors/lenovo) (Hardware): version not specified
- [V130-15igm Firmware](https://www.precursorintelligence.com/product/lenovo/v130-15igm_firmware) by [Lenovo](https://www.precursorintelligence.com/vendors/lenovo) (Operating system): version not specified
- [V330-15ikb](https://www.precursorintelligence.com/product/lenovo/v330-15ikb) by [Lenovo](https://www.precursorintelligence.com/vendors/lenovo) (Hardware): version not specified
- [V330-15ikb Firmware](https://www.precursorintelligence.com/product/lenovo/v330-15ikb_firmware) by [Lenovo](https://www.precursorintelligence.com/vendors/lenovo) (Operating system): version not specified
- [V330-15isk](https://www.precursorintelligence.com/product/lenovo/v330-15isk) by [Lenovo](https://www.precursorintelligence.com/vendors/lenovo) (Hardware): version not specified
- [V330-15isk Firmware](https://www.precursorintelligence.com/product/lenovo/v330-15isk_firmware) by [Lenovo](https://www.precursorintelligence.com/vendors/lenovo) (Operating system): version not specified
- [Yoga S730-13iml](https://www.precursorintelligence.com/product/lenovo/yoga_s730-13iml) by [Lenovo](https://www.precursorintelligence.com/vendors/lenovo) (Hardware): version not specified
- [Yoga S730-13iml Firmware](https://www.precursorintelligence.com/product/lenovo/yoga_s730-13iml_firmware) by [Lenovo](https://www.precursorintelligence.com/vendors/lenovo) (Operating system): version not specified
- [Yoga S940-14iil](https://www.precursorintelligence.com/product/lenovo/yoga_s940-14iil) by [Lenovo](https://www.precursorintelligence.com/vendors/lenovo) (Hardware): version not specified
- [Yoga S940-14iil Firmware](https://www.precursorintelligence.com/product/lenovo/yoga_s940-14iil_firmware) by [Lenovo](https://www.precursorintelligence.com/vendors/lenovo) (Operating system): version not specified
- [Yoga S940-14iwl](https://www.precursorintelligence.com/product/lenovo/yoga_s940-14iwl) by [Lenovo](https://www.precursorintelligence.com/vendors/lenovo) (Hardware): version not specified
- [Yoga S940-14iwl Firmware](https://www.precursorintelligence.com/product/lenovo/yoga_s940-14iwl_firmware) by [Lenovo](https://www.precursorintelligence.com/vendors/lenovo) (Operating system): version not specified

## How do I fix CVE-2021-3453?

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

- [support.lenovo.com](https://support.lenovo.com/us/en/product_security/LEN-65529) (Vendor advisory)

## Questions

### What is CVE-2021-3453?

CVE-2021-3453 is a medium-severity flaw in Thinkpad Helix Firmware from Lenovo, published on 16 July 2021. An attacker has to be physically at the device without logging in, and nobody has to click anything. If it works, the attacker can change data.

### How serious is CVE-2021-3453?

It scores 4.6 out of 10 on the CVSS severity scale, which is medium. Our risk score for CVE-2021-3453 is 21 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-2021-3453 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-2021-3453 affect?

For Thinkpad Helix Firmware from Lenovo: n17etb4w. The record lists 42 products in all, each with its versions, under "Who is affected" on this page.

### How do I fix CVE-2021-3453?

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-2021-3453 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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