How severe is CVE-2023-4420?

CVE-2023-4420 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2023-4420 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (16th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2023-4420?

CVE-2023-4420 primarily affects Sick Lms531 Firmware. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2023-4420?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2023-4420 published?

CVE-2023-4420 was published on 2023-08-24 and last updated on 2026-06-17.

CVE-2023-4420

CVE-2023-4420 is a critical-severity vulnerability in Sick Lms531 Firmware with a CVSS 3.x base score of 9.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-311.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
EPSS exploit prediction: 0% (16th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-311
Affected product: Sick Lms531 Firmware
Published: 2023-08-24
Last modified: 2026-06-17

Description

A remote unprivileged attacker can intercept the communication via e.g. Man-In-The-Middle, due to the absence of Transport Layer Security (TLS) in the SICK LMS5xx. This lack of encryption in the communication channel can lead to the unauthorized disclosure of sensitive information. The attacker can exploit this weakness to eavesdrop on the communication between the LMS5xx and the Client, and potentially manipulate the data being transmitted.

Frequently asked questions

What is CVE-2023-4420?: A remote unprivileged attacker can intercept the communication via e.g. Man-In-The-Middle, due to the absence of Transport Layer Security (TLS) in the SICK LMS5xx. This lack of encryption in the communication channel can lead to the unauthorized disclosure of sensitive information. The attacker can exploit this weakness to eavesdrop on the communication between the LMS5xx and the Client, and potentially manipulate the data being transmitted.
How severe is CVE-2023-4420?: CVE-2023-4420 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2023-4420 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (16th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2023-4420?: CVE-2023-4420 primarily affects Sick Lms531 Firmware. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2023-4420?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2023-4420 published?: CVE-2023-4420 was published on 2023-08-24 and last updated on 2026-06-17.

References

Affected products (3)

cpe:2.3:o:sick:lms531_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:sick:lms511_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:sick:lms500_firmware:*:*:*:*:*:*:*:*

More vulnerabilities in Sick Lms531 Firmware

CVE-2023-4419 — Critical (CVSS 9.8): The LMS5xx uses hard-coded credentials, which potentially allow low-skilled unauthorized remote attackers to…
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