CVE-2021-34753 json
Cisco Firepower Threat Defense Ethernet Industrial Protocol Policy Bypass Vulnerabilities
published 2024-11-15 23 mo ago modified 2026-08-11 2 mo ago also EUVD-2021-21403
- cvss
- 5.8
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.7%
- EPSS 0.7% chance of exploitation in 30 days, percentile 51%
- public exploits
- 0
- none known
Summary
A vulnerability in the payload inspection for Ethernet Industrial Protocol (ENIP) traffic for Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to bypass configured rules for ENIP traffic.
This vulnerability is due to incomplete processing during deep packet inspection for ENIP packets. An attacker could exploit this vulnerability by sending a crafted ENIP packet to the targeted interface. A successful exploit could allow the attacker to bypass configured access control and intrusion policies that should trigger and drop for the ENIP packet.
Patch / fix
- cisco firepower_threat_defense_software 6.4.0.13, 6.6.5.1, 6.7.0.3, 7.0.1
CISA SSVC
- Exploitation
- none
- Automatable
- yes
- Technical impact
- partial
- Assessed
- 23 mo ago
Exploit prediction
0.66% chance of exploitation in the next 30 days, higher than 51% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 5.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N |
| NVD | 3.1 | 5.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N |
Affected products
- Cisco Cisco Firepower Threat Defense Software
- cisco firepower_threat_defense_software
Classification
- Weakness
-
- CWE-284 Improper Access Control
References
Sources
- CVE List CVE-2021-34753
- NVD CVE-2021-34753
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