CVE-2020-3166: Cisco FXOS Software CLI Arbitrary File Read and Write Vulnerability

Severity: medium (CVSS 6.7 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2020-02-26 · updated 2026-08-11
Weakness: CWE-20

Description

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.

Affected products

Cisco ASA Software: from 9.8 before 9.9.2.66; from 9.10 before 9.13.1.5 — fixed in 9.13.1.5, 9.9.2.66
Cisco Firepower Extensible Operating System (FXOS): before 2.2.2.97; from 2.3 before 2.3.1.155; from 2.4 before 2.4.1.238; from 2.6 before 2.6.1.157 — fixed in 2.2.2.97, 2.3.1.155, 2.4.1.238, 2.6.1.157
Cisco Firepower Threat Defense Software: from 6.2.2 before 6.2.3.16; from 6.3.0 before 6.5.0.3 — fixed in 6.2.3.16, 6.5.0.3

How to fix

Upgrade to a fixed version: Cisco ASA Software 9.13.1.5, 9.9.2.66; Cisco Firepower Extensible Operating System (FXOS) 2.2.2.97, 2.3.1.155, 2.4.1.238, 2.6.1.157; Cisco Firepower Threat Defense Software 6.2.3.16, 6.5.0.3. Check the vendor advisory for mitigations.

References

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