CVE-2023-40143: An attacker with access to the Westermo Lynx web application that has the vulnerable software could introduce

Routine

MEDIUM 5.4MITIGATE

CVE-2023-40143 is a medium-severity flaw (CVSS 5.4) affecting l206-f2g firmware. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

An attacker with access to the Westermo Lynx web application that has the vulnerable software could introduce arbitrary JavaScript by injecting a cross-site scripting payload into the "forward.0.domain" parameter.

Why this priority

No elevated risk signals yet

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	5.4 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	0.3% (top 78%)
CISA exploited list	No
Weakness	CWE-79
Published	2024-02-06
Last modified	2026-06-17

Publisher (CNA): ICS-CERT · Vendor: westermo

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

Am I affected?

Timeline

2024-02-06 22:16 UTCPublished CVE record published
2026-06-17 06:16 UTCUpdated Record last modified

westermo l206-f2g firmware MITIGATE

Affected: 4.24

Fixed in: no fixed release known

Safe to downgrade to: a release before 4.24

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-2023-40143?

l206-f2g firmware: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2023-40143 being exploited?

CVE-2023-40143 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-2023-40143 affect?

CVE-2023-40143 affects l206-f2g firmware. Severity is medium (CVSS 5.4). An attacker with access to the Westermo Lynx web application that has the vulnerable software could introduce arbitrary JavaScript by injecting a cross-site scripting payload into the "forward.0.domain" parameter.

How urgent is CVE-2023-40143?

Priority 24/100. No elevated risk signals yet.

Related CVEs

CVE-2023-45735 HIGH 8.0 MITIGATE A potential attacker with access to the Westermo Lynx device may be able to execute malicious code that c
CVE-2023-45227 MEDIUM 5.4 MITIGATE An attacker with access to the web application with vulnerable software could introduce arbitra
CVE-2023-45222 MEDIUM 5.4 MITIGATE An attacker with access to the web application that has the vulnerable software could introduce arbitrary J
CVE-2023-45213 MEDIUM 6.6 MITIGATE A potential attacker with access to the Westermo Lynx device would be able to execute malicious code th
CVE-2023-42765 MEDIUM 5.4 MITIGATE An attacker with access to the vulnerable software could introduce arbitrary JavaScript by injecting

References

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