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Fencer Intel
medium 4.2

CVE-2020-3166 json

Cisco FXOS Software CLI Arbitrary File Read and Write Vulnerability

published 6y ago modified 2mo ago also EUVD-2020-24437

cvss
4.2
version 3.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 21%
public exploits
0
none known

Summary

A vulnerability in the CLI of Cisco FXOS Software could allow an authenticated, local attacker to read or write arbitrary files on the underlying operating system (OS). The vulnerability is due to insufficient input validation. An attacker could exploit this vulnerability by including crafted arguments to a specific CLI command. A successful exploit could allow the attacker to read or write to arbitrary files on the underlying OS.

Patch / fix

  • cisco secure_firewall_threat_defense 6.2.3.16, 6.5.0.3
  • cisco adaptive_security_appliance_software 9.9.2.66, 9.13.1.5
  • cisco firepower_extensible_operating_system 2.2.2.97, 2.3.1.155, 2.4.1.238, 2.6.1.157

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CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
last yr.

Exploit prediction

0.29% chance of exploitation in the next 30 days, higher than 21% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
CNA 3.0 4.2 CVSS:3.0/AV:L/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:L
NVD 3.1 6.7 CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 4.6 AV:L/AC:L/Au:N/C:P/I:P/A:P

Affected products

  • Cisco Cisco Firepower Extensible Operating System (FXOS)

Classification

Weakness
  • CWE-20 Improper Input Validation

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.