Cyber Resilience

CVE-2021-21002

High

Published: 25 June 2021

Published
25 June 2021
Modified
21 November 2024
KEV Added
—
Patch
—
CVSS Score v3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS Score 0.0033 56.7th percentile
Risk Priority 15 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-21002 is a high-severity Missing Release of Resource after Effective Lifetime (CWE-772) vulnerability in Phoenixcontact Fl Comserver Uni 232\/422\/485 Firmware. Its CVSS base score is 7.5 (High).

Operationally, ranked in the top 43.3% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

In Phoenix Contact FL COMSERVER UNI in versions < 2.40 a invalid Modbus exception response can lead to a temporary denial of service.

CWE(s)
CWE-772

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

phoenixcontact
fl comserver uni 232\/422\/485 firmware
≤ 2.40
phoenixcontact
fl comserver uni 232\/422\/485-t firmware
≤ 2.40

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

SC-10 Network Disconnect
addresses: CWE-772

Ensures network resources are released once the session ends or becomes inactive, closing the window for missing-release weaknesses.

References