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Fencer Intel
medium 5.8

CVE-2021-34754 json

Cisco Firepower Threat Defense Software Ethernet Industrial Protocol Policy Bypass Vulnerabilities

published 5y ago modified 2mo ago also EUVD-2021-21404

cvss
5.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
1.0%
EPSS 1.0% chance of exploitation in 30 days, percentile 63%
public exploits
0
none known

Summary

Multiple vulnerabilities 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. These vulnerabilities are due to incomplete processing during deep packet inspection for ENIP packets. An attacker could exploit these vulnerabilities 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 be activated for the ENIP packet.

Patch / fix

  • cisco secure_firewall_threat_defense 6.4.0.13, 6.6.5.1, 6.7.0.3, 7.0.1

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CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
2y ago

Exploit prediction

1.01% chance of exploitation in the next 30 days, higher than 63% of all scored CVEs (FIRST EPSS, 2026-11-09).

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 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
NVD 2.0 5.0 AV:N/AC:L/Au:N/C:N/I:P/A:N

Affected products

  • Cisco Cisco Firepower Threat Defense Software

Classification

Weakness

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.