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Fencer Intel
medium 5.8

CVE-2021-1494 json

Multiple Cisco products are affected by a vulnerability in the Snort detection engine that could allow an unauthenticated, remote attacker…

published last yr. modified 4mo ago also EUVD-2021-6961

cvss
5.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
1.1%
EPSS 1.1% chance of exploitation in 30 days, percentile 65%
public exploits
0
none known

Summary

Multiple Cisco products are affected by a vulnerability in the Snort detection engine that could allow an unauthenticated, remote attacker to bypass a configured file policy for HTTP. The vulnerability is due to incorrect handling of specific HTTP header parameters. An attacker could exploit this vulnerability by sending crafted HTTP packets through an affected device. A successful exploit could allow the attacker to bypass a configured file policy for HTTP packets and deliver a malicious payload.

Patch / fix

  • cisco firepower_threat_defense_software 6.4.0.12, 6.6.4, 6.7.0.2
  • cisco utd_snort_ips_engine_software 16.12.5, 17.3.3, 17.4.1

Is CVE-2021-1494 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
last yr.

Exploit prediction

1.10% chance of exploitation in the next 30 days, higher than 65% 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

Affected products

  • Cisco Cisco Firepower Threat Defense Software
  • Cisco Cisco UTD SNORT IPS Engine Software
  • cisco firepower_threat_defense_software
  • cisco utd_snort_ips_engine_software

Classification

Weakness
  • CWE-693 Protection Mechanism Failure

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.