How severe is CVE-2020-6991?

CVE-2020-6991 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-2020-6991 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (66th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-6991?

CVE-2020-6991 primarily affects Moxa Eds-g516e Firmware. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2020-6991?

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-2020-6991 published?

CVE-2020-6991 was published on 2020-03-24 and last updated on 2026-06-17.

CVE-2020-6991

CVE-2020-6991 is a critical-severity vulnerability in Moxa Eds-g516e 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-521.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 5.0
EPSS exploit prediction: 1% (66th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-521
Affected product: Moxa Eds-g516e Firmware
Published: 2020-03-24
Last modified: 2026-06-17

Description

In Moxa EDS-G516E Series firmware, Version 5.2 or lower, weak password requirements may allow an attacker to gain access using brute force.

Frequently asked questions

What is CVE-2020-6991?: In Moxa EDS-G516E Series firmware, Version 5.2 or lower, weak password requirements may allow an attacker to gain access using brute force.
How severe is CVE-2020-6991?: CVE-2020-6991 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-2020-6991 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (66th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-6991?: CVE-2020-6991 primarily affects Moxa Eds-g516e Firmware. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2020-6991?: 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-2020-6991 published?: CVE-2020-6991 was published on 2020-03-24 and last updated on 2026-06-17.

References

https://www.us-cert.gov/ics/advisories/icsa-20-056-04

Affected products (2)

cpe:2.3:o:moxa:eds-g516e_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:moxa:eds-510e_firmware:*:*:*:*:*:*:*:*

More vulnerabilities in Moxa Eds-g516e Firmware

CVE-2020-7007 — Critical (CVSS 9.8): In Moxa EDS-G516E Series firmware, Version 5.2 or lower, the attacker may execute arbitrary codes or target the device,…
CVE-2020-6981 — Critical (CVSS 9.8): In Moxa EDS-G516E Series firmware, Version 5.2 or lower, an attacker may gain access to the system without proper…
CVE-2020-7001 — High (CVSS 7.5): In Moxa EDS-G516E Series firmware, Version 5.2 or lower, the affected products use a weak cryptographic algorithm,…
CVE-2020-6997 — High (CVSS 7.5): In Moxa EDS-G516E Series firmware, Version 5.2 or lower, sensitive information is transmitted over some web…
CVE-2020-6979 — High (CVSS 7.5): In Moxa EDS-G516E Series firmware, Version 5.2 or lower, the affected products use a hard-coded cryptographic key,…
CVE-2019-19707 — High (CVSS 7.5): On Moxa EDS-G508E, EDS-G512E, and EDS-G516E devices (with firmware through 6.0), denial of service can occur via…

All CVEs affecting Moxa Eds-g516e Firmware →

Other CWE-521 (Weak Password Requirements) vulnerabilities

CVE-2026-25715 — Critical (CVSS 9.8): The web management interface of the device allows the administrator username and password to be set to blank values.…
CVE-2025-53963 — Critical (CVSS 9.8): An issue was discovered on Thermo Fisher Ion Torrent OneTouch 2 INS1005527 devices. They run an SSH server accessible…
CVE-2025-63747 — Critical (CVSS 9.8): QaTraq 6.9.2 ships with administrative account credentials which are enabled in default installations and permit…
CVE-2025-12552 — Critical (CVSS 9.8): Insufficient Password Policy.This issue affects BLU-IC2: through 1.19.5; BLU-IC4: through 1.19.5.
CVE-2025-11200 — Critical (CVSS 9.8): MLflow Weak Password Requirements Authentication Bypass Vulnerability. This vulnerability allows remote attackers to…
CVE-2025-12364 — Critical (CVSS 9.8): Weak Password Policy.This issue affects BLU-IC2: through 1.19.5; BLU-IC4: through 1.19.5.

Browse all CWE-521 (Weak Password Requirements) vulnerabilities →