# What is CVE-2021-3675?

> CVE-2021-3675 is a high-severity flaw (CVSS 7.1) in Fingerprint Driver from Synaptics, published on 16 June 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 0.3%. If you run an affected version, plan in the vendor’s fix.

Canonical page: https://www.precursorintelligence.com/what-is/cve-2021-3675

## 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:** 45 out of 100 (Medium); action: Plan remediation. Kept up to date as the evidence changes.
- **Severity:** High (CVSS 7.1 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:** 16 June 2022
- **Record last updated:** 26 June 2023
- **Main product:** Fingerprint Driver from Synaptics
- **Affected products:** 1

## What is CVE-2021-3675? In plain terms

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

### The official description

Improper Input Validation vulnerability in synaTEE.signed.dll of Synaptics Fingerprint Driver allows a local authorized attacker to overwrite a heap tag, with potential loss of confidentiality. This issue affects: Synaptics Synaptics Fingerprint Driver 5.1.xxx.26 versions prior to xxx=340 on x86/64; 5.2.xxxx.26 versions prior to xxxx=3541 on x86/64; 5.2.2xx.26 versions prior to xx=29 on x86/64; 5.2.3xx.26 versions prior to xx=25 on x86/64; 5.3.xxxx.26 versions prior to xxxx=3543 on x86/64; 5.5.xx.1058 versions prior to xx=44 on x86/64; 5.5.xx.1102 versions prior to xx=34 on x86/64; 5.5.xx.1116 versions prior to xx=14 on x86/64; 6.0.xx.1104 versions prior to xx=50 on x86/64; 6.0.xx.1108 versions prior to xx=31 on x86/64; 6.0.xx.1111 versions prior to xx=58 on x86/64.

### What kind of flaw is it?

- CWE-787: Out-of-bounds Write
- CWE-20: Improper Input Validation

### 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 ordinary user account
- Does someone have to click: No, nobody has to do anything
- What an attacker gets: Can read data and take it offline

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

## Is CVE-2021-3675 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

- 16 June 2022: Published
- 26 June 2023: Record last updated

### How Precursor Intelligence ranks it

CVE-2021-3675 scores **45 out of 100 (Medium)**, with the action "Plan remediation".

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-2021-3675?

The published record lists 1 product. Versions are as published: "5.1.000.26 to before 5.1.340.26" means from 5.1.000.26 up to, but not including, 5.1.340.26.

- [Fingerprint Driver](https://www.precursorintelligence.com/product/synaptics/fingerprint_driver) by [Synaptics](https://www.precursorintelligence.com/vendors/synaptics) (Application): 5.1.000.26 to before 5.1.340.26, 5.2.0000.26 to before 5.2.3541.26, 5.3.0000.26 to before 5.3.3543.26, 5.5.00.1058 to before 5.5.44.1058, 6.0.00.1111 to before 6.0.58.1111

## How do I fix CVE-2021-3675?

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 advisories and patch notes 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.hp.com](https://support.hp.com/us-en/document/ish_6411153-6411191-16/hpsbhf03797) (Patch, Third-party advisory)
- [synaptics.com](https://synaptics.com/sites/default/files/2022-06/fingerprint-driver-SGX-security-brief-2022-06-14.pdf) (Vendor advisory)
- [support.lenovo.com](https://support.lenovo.com/us/en/product_security/LEN-68054) (Third-party advisory)

## Questions

### What is CVE-2021-3675?

CVE-2021-3675 is a high-severity flaw in Fingerprint Driver from Synaptics, published on 16 June 2022. An attacker has to be already on the device with an ordinary user account, and nobody has to click anything. If it works, the attacker can read data and take it offline.

### How serious is CVE-2021-3675?

It scores 7.1 out of 10 on the CVSS severity scale, which is high. Our risk score for CVE-2021-3675 is 45 out of 100, which is Medium. Its action is "Plan remediation". No sign of exploitation and a low forecast. Patch it in your normal update cycle.

### Is CVE-2021-3675 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-2021-3675 affect?

For Fingerprint Driver from Synaptics: 5.1.000.26 to before 5.1.340.26, 5.2.0000.26 to before 5.2.3541.26, 5.3.0000.26 to before 5.3.3543.26, 5.5.00.1058 to before 5.5.44.1058, 6.0.00.1111 to before 6.0.58.1111.

### How do I fix CVE-2021-3675?

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-2021-3675 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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