CVE-2021-42852: A command injection vulnerability was reported in some Lenovo Personal Cloud Storage devices that could allow

Q: How do I fix CVE-2021-42852?

a1 firmware: upgrade to 5.3.6.a1; t1 firmware: upgrade to 5.3.6.t1; x1 firmware: upgrade to 5.3.8.x1. Exact commands for each OS are on this page.

Q: Is CVE-2021-42852 being exploited?

CVE-2021-42852 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2021-42852 affect?

CVE-2021-42852 affects a1 firmware, t1 firmware, x1 firmware. Severity is high (CVSS 8.0). A command injection vulnerability was reported in some Lenovo Personal Cloud Storage devices that could allow an authenticated user to execute operating system commands by sending a crafted packet to the device.

This month

HIGH 8.0UPGRADEUPGRADEUPGRADE

CVE-2021-42852 is a high-severity flaw (CVSS 8.0) affecting a1 firmware, t1 firmware, x1 firmware. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

A command injection vulnerability was reported in some Lenovo Personal Cloud Storage devices that could allow an authenticated user to execute operating system commands by sending a crafted packet to the device.

Why this priority

High severity

A fixed release or distro patch exists.

Risk facts

CVSS score	8.0 (High)
Attack vector	Adjacent network
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	0.8% (top 44%)
CISA exploited list	No
Weakness	CWE-78
Published	2022-05-18
Last modified	2026-06-17

Publisher (CNA): Lenovo Group Ltd. · Vendor: lenovo

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2022-05-18 16:15 UTCPublished CVE record published
2026-06-17 04:10 UTCUpdated Record last modified

lenovo a1 firmware UPGRADE

Affected: < 5.3.6.a1

Fixed in: 5.3.6.a1

Safe to downgrade to: no unaffected older release

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

lenovo t1 firmware UPGRADE

Affected: < 5.3.6.t1

Fixed in: 5.3.6.t1

Safe to downgrade to: no unaffected older release

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

lenovo x1 firmware UPGRADE

Affected: < 5.3.8.x1

Fixed in: 5.3.8.x1

Safe to downgrade to: no unaffected older release

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

lenovo t2 firmware UPGRADE

Affected: < 5.3.8.t2

Fixed in: 5.3.8.t2

Safe to downgrade to: no unaffected older release

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

lenovo t2pro firmware UPGRADE

Affected: < 5.3.7.t2-pro

Fixed in: 5.3.7.t2-pro

Safe to downgrade to: no unaffected older release

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2021-42852?

a1 firmware: upgrade to 5.3.6.a1; t1 firmware: upgrade to 5.3.6.t1; x1 firmware: upgrade to 5.3.8.x1. Exact commands for each OS are on this page.

Is CVE-2021-42852 being exploited?

CVE-2021-42852 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2021-42852 affect?

CVE-2021-42852 affects a1 firmware, t1 firmware, x1 firmware. Severity is high (CVSS 8.0). A command injection vulnerability was reported in some Lenovo Personal Cloud Storage devices that could allow an authenticated user to execute operating system commands by sending a crafted packet to the device.

How urgent is CVE-2021-42852?

Priority 42/100. High severity

Software pages

Lenovo vulnerabilities

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References

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