CVE-2020-3455

highpriority · track · 31EPSS 0.003 · 28 %ileEURUUS
grimoire priorityP2 · Scheduled
Exploitable?
—
no known exploitation
Likely / severe?
0.35% (28th) EPSS
CVSS 7.2 · high
Is it mine?
43 products
Check your exposure
Who says so?
4 sources
cnnvd · enisa_euvd · fstec_bdu · cisco_csaf

EPSS · scored 2026-10-27

A vulnerability in the secure boot process of Cisco FXOS Software could allow an authenticated, local attacker to bypass the secure boot mechanisms. The vulnerability is due to insufficient protections of the secure boot process. An attacker could exploit this vulnerability by injecting code into a specific file that is then referenced during the device boot process. A successful exploit could allow the attacker to break the chain of trust and inject code into the boot process of the device which would be executed at each boot and maintain persistence across reboots.

01

remediations

Vendor fix, mitigation, or workaround guidance, as published by each source.

A vendor fix is available.

  • FixedCisco Firepower Extensible Operating System (FXOS) 2.2.1.63 when installed on Cisco Firepower 4100 Seriescisco_csaf

    Cisco has released software updates that address this vulnerability.

    https://software.cisco.com
  • FixedCisco Firepower Extensible Operating System (FXOS) 2.2.1.70 when installed on Cisco Firepower 4100 Seriescisco_csaf

    Cisco has released software updates that address this vulnerability.

    https://software.cisco.com
  • FixedCisco Firepower Extensible Operating System (FXOS) 2.2.1.70 when installed on Cisco Firepower 9000 Seriescisco_csaf

    Cisco has released software updates that address this vulnerability.

    https://software.cisco.com
  • FixedCisco Firepower Extensible Operating System (FXOS) 2.2.2.137 when installed on Cisco Firepower 4100 Seriescisco_csaf

    Cisco has released software updates that address this vulnerability.

    https://software.cisco.com
  • FixedCisco Firepower Extensible Operating System (FXOS) 2.2.2.137 when installed on Cisco Firepower 9000 Seriescisco_csaf

    Cisco has released software updates that address this vulnerability.

    https://software.cisco.com
  • FixedCisco Firepower Extensible Operating System (FXOS) 2.2.2.17 when installed on Cisco Firepower 4100 Seriescisco_csaf

    Cisco has released software updates that address this vulnerability.

    https://software.cisco.com
  • FixedCisco Firepower Extensible Operating System (FXOS) 2.2.2.26 when installed on Cisco Firepower 9000 Seriescisco_csaf

    Cisco has released software updates that address this vulnerability.

    https://software.cisco.com
  • FixedCisco Firepower Extensible Operating System (FXOS) 2.2.2.28 when installed on Cisco Firepower 4100 Seriescisco_csaf

    Cisco has released software updates that address this vulnerability.

    https://software.cisco.com
  • FixedCisco Firepower Extensible Operating System (FXOS) 2.2.2.28 when installed on Cisco Firepower 9000 Seriescisco_csaf

    Cisco has released software updates that address this vulnerability.

    https://software.cisco.com
  • FixedCisco Firepower Extensible Operating System (FXOS) 2.2.2.54 when installed on Cisco Firepower 4100 Seriescisco_csaf

    Cisco has released software updates that address this vulnerability.

    https://software.cisco.com
  • FixedCisco Firepower Extensible Operating System (FXOS) 2.2.2.60 when installed on Cisco Firepower 9000 Seriescisco_csaf

    Cisco has released software updates that address this vulnerability.

    https://software.cisco.com
  • FixedCisco Firepower Extensible Operating System (FXOS) 2.2.2.83 when installed on Cisco Firepower 9000 Seriescisco_csaf

    Cisco has released software updates that address this vulnerability.

    https://software.cisco.com
  • FixedCisco Firepower Extensible Operating System (FXOS) 2.2.2.97 when installed on Cisco Firepower 9000 Seriescisco_csaf

    Cisco has released software updates that address this vulnerability.

    https://software.cisco.com
  • FixedCisco Firepower Extensible Operating System (FXOS) 2.3.1.110 when installed on Cisco Firepower 4100 Seriescisco_csaf

    Cisco has released software updates that address this vulnerability.

    https://software.cisco.com
  • FixedCisco Firepower Extensible Operating System (FXOS) 2.3.1.111 when installed on Cisco Firepower 4100 Seriescisco_csaf

    Cisco has released software updates that address this vulnerability.

    https://software.cisco.com
  • FixedCisco Firepower Extensible Operating System (FXOS) 2.3.1.111 when installed on Cisco Firepower 9000 Seriescisco_csaf

    Cisco has released software updates that address this vulnerability.

    https://software.cisco.com
  • FixedCisco Firepower Extensible Operating System (FXOS) 2.3.1.130 when installed on Cisco Firepower 4100 Seriescisco_csaf

    Cisco has released software updates that address this vulnerability.

    https://software.cisco.com
  • FixedCisco Firepower Extensible Operating System (FXOS) 2.3.1.144 when installed on Cisco Firepower 4100 Seriescisco_csaf

    Cisco has released software updates that address this vulnerability.

    https://software.cisco.com
  • FixedCisco Firepower Extensible Operating System (FXOS) 2.3.1.145 when installed on Cisco Firepower 4100 Seriescisco_csaf

    Cisco has released software updates that address this vulnerability.

    https://software.cisco.com
  • FixedCisco Firepower Extensible Operating System (FXOS) 2.3.1.155 when installed on Cisco Firepower 9000 Seriescisco_csaf

    Cisco has released software updates that address this vulnerability.

    https://software.cisco.com
  • FixedCisco Firepower Extensible Operating System (FXOS) 2.3.1.166 when installed on Cisco Firepower 9000 Seriescisco_csaf

    Cisco has released software updates that address this vulnerability.

    https://software.cisco.com
  • FixedCisco Firepower Extensible Operating System (FXOS) 2.3.1.179 when installed on Cisco Firepower 4100 Seriescisco_csaf

    Cisco has released software updates that address this vulnerability.

    https://software.cisco.com
  • FixedCisco Firepower Extensible Operating System (FXOS) 2.3.1.56 when installed on Cisco Firepower 4100 Seriescisco_csaf

    Cisco has released software updates that address this vulnerability.

    https://software.cisco.com
  • FixedCisco Firepower Extensible Operating System (FXOS) 2.3.1.58 when installed on Cisco Firepower 4100 Seriescisco_csaf

    Cisco has released software updates that address this vulnerability.

    https://software.cisco.com
  • FixedCisco Firepower Extensible Operating System (FXOS) 2.3.1.58 when installed on Cisco Firepower 9000 Seriescisco_csaf

    Cisco has released software updates that address this vulnerability.

    https://software.cisco.com
  • FixedCisco Firepower Extensible Operating System (FXOS) 2.3.1.88 when installed on Cisco Firepower 4100 Seriescisco_csaf

    Cisco has released software updates that address this vulnerability.

    https://software.cisco.com
  • FixedCisco Firepower Extensible Operating System (FXOS) 2.3.1.88 when installed on Cisco Firepower 9000 Seriescisco_csaf

    Cisco has released software updates that address this vulnerability.

    https://software.cisco.com
  • FixedCisco Firepower Extensible Operating System (FXOS) 2.3.1.91 when installed on Cisco Firepower 9000 Seriescisco_csaf

    Cisco has released software updates that address this vulnerability.

    https://software.cisco.com
  • FixedCisco Firepower Extensible Operating System (FXOS) 2.3.1.99 when installed on Cisco Firepower 9000 Seriescisco_csaf

    Cisco has released software updates that address this vulnerability.

    https://software.cisco.com
  • FixedCisco Firepower Extensible Operating System (FXOS) 2.6.1.131 when installed on Cisco Firepower 4100 Seriescisco_csaf

    Cisco has released software updates that address this vulnerability.

    https://software.cisco.com
  • FixedCisco Firepower Extensible Operating System (FXOS) 2.6.1.131 when installed on Cisco Firepower 9000 Seriescisco_csaf

    Cisco has released software updates that address this vulnerability.

    https://software.cisco.com
  • FixedCisco Firepower Extensible Operating System (FXOS) 2.6.1.166 when installed on Cisco Firepower 4100 Seriescisco_csaf

    Cisco has released software updates that address this vulnerability.

    https://software.cisco.com
  • FixedCisco Firepower Extensible Operating System (FXOS) 2.6.1.169 when installed on Cisco Firepower 4100 Seriescisco_csaf

    Cisco has released software updates that address this vulnerability.

    https://software.cisco.com
  • FixedCisco Firepower Extensible Operating System (FXOS) 2.6.1.169 when installed on Cisco Firepower 9000 Seriescisco_csaf

    Cisco has released software updates that address this vulnerability.

    https://software.cisco.com
  • FixedCisco Firepower Extensible Operating System (FXOS) 2.6.1.174 when installed on Cisco Firepower 4100 Seriescisco_csaf

    Cisco has released software updates that address this vulnerability.

    https://software.cisco.com
  • FixedCisco Firepower Extensible Operating System (FXOS) 2.6.1.192 when installed on Cisco Firepower 9000 Seriescisco_csaf

    Cisco has released software updates that address this vulnerability.

    https://software.cisco.com
02

cvss

Technical severity, 0–10. One row per scoring source.

7.8
010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 6.7–7.8

v2.07.2highAV:L/AC:L/Au:N/C:C/I:C/A:Cprimary · NVD / NIST USexploitability 3.9 · impact 10
v3.17.8highCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:Hprimary · NVD / NIST USexploitability 1.8 · impact 5.9
v3.06.7mediumCVSS:3.0/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:Hsecondary · ENISA EU
v3.06.7mediumCVSS:3.0/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:Hsecondary · psirt@cisco.com USexploitability 0.8 · impact 5.9
v3.06.7mediumCVSS:3.0/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:Hsecondary · Cisco PSIRT US
v3.16.7mediumAV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:Hsecondary · FSTEC (BDU) RU
v3.17.1highCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:Usecondary · CVSS-BT (t0sche)
03

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Exploitation: none · Automatable: no · Technical Impact: totalcoordinatorcisa_ssvcUS
04

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-693USCWE-693US
05

affected products (43)

Products and version ranges known to be affected.

showing 20 of 43
06

advisories (1)

Vendor and ecosystem advisories describing this.

  • cisco-sa-fxos-sbbp-XTuPkYTnCisco FXOS Software for Firepower 4100/9300 Series Appliances Secure Boot Bypass Vulnerability2020-10-21csaf · cisco_csafUS

    A vulnerability in the secure boot process of Cisco FXOS Software could allow an authenticated, local attacker to bypass the secure boot mechanisms. The vulnerability is due to insufficient protections of the secure boot process. An attacker could exploit this vulnerability by injecting code into a specific file that is then referenced during the device boot process. A successful exploit could allow the attacker to break the chain of trust and inject code into the boot process of the device which would be executed at each boot and maintain persistence across reboots. Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability.

07

also known as (4)

Other names and identifiers for this entity.

08

sources

Which sources assert this record, and when.

cnnvdenisa_euvdfstec_bducisco_csafNVDCVE.orgMITRE
published 2020-10-21modified 2026-06-17
09

references (6)

External citations — patches, advisories, analysis.

scry

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