How severe is CVE-2020-6087?

CVE-2020-6087 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2020-6087 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 4% (88th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-6087?

CVE-2020-6087 affects Rockwellautomation Flex I/o 1794-aent/b Firmware. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2020-6087?

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

When was CVE-2020-6087 published?

CVE-2020-6087 was published on 2020-10-14 and last updated on 2026-06-17.

CVE-2020-6087

CVE-2020-6087 is a high-severity vulnerability in Rockwellautomation Flex I/o 1794-aent/b Firmware with a CVSS 3.x base score of 7.5. 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-120.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 7.8
EPSS exploit prediction: 4% (88th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-120
Affected product: Rockwellautomation Flex I/o 1794-aent/b Firmware
Published: 2020-10-14
Last modified: 2026-06-17

Description

An exploitable denial of service vulnerability exists in the ENIP Request Path Data Segment functionality of Allen-Bradley Flex IO 1794-AENT/B. A specially crafted network request can cause a loss of communications with the device resulting in denial-of-service. An attacker can send a malicious packet to trigger this vulnerability If the ANSI Extended Symbol Segment Sub-Type is supplied, the device treats the byte following as the Data Size in words. When this value represents a size greater than what remains in the packet data, the device enters a fault state where communication with the device is lost and a physical power cycle is required.

Frequently asked questions

What is CVE-2020-6087?: An exploitable denial of service vulnerability exists in the ENIP Request Path Data Segment functionality of Allen-Bradley Flex IO 1794-AENT/B. A specially crafted network request can cause a loss of communications with the device resulting in denial-of-service. An attacker can send a malicious packet to trigger this vulnerability If the ANSI Extended Symbol Segment Sub-Type is supplied, the device treats the byte following as the Data Size in words. When this value represents a size greater than what remains in the packet data, the device enters a fault state where communication with the device is lost and a physical power cycle is required.
How severe is CVE-2020-6087?: CVE-2020-6087 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2020-6087 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 4% (88th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-6087?: CVE-2020-6087 affects Rockwellautomation Flex I/o 1794-aent/b Firmware. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2020-6087?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2020-6087 published?: CVE-2020-6087 was published on 2020-10-14 and last updated on 2026-06-17.

References

https://talosintelligence.com/vulnerability_reports/TALOS-2020-1007

Affected products (1)

cpe:2.3:o:rockwellautomation:flex_i\/o_1794-aent\/b_firmware:4.003:*:*:*:*:*:*:*

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