CVE-2020-3557

mediumpriority · track · 21EPSS 0.007 · 54 %ileEURUUS

grimoire priorityP3 · Track

Exploitable?

—

no known exploitation

Likely / severe?

0.73% (54th) EPSS

CVSS 5 · medium

Is it mine?

20 products

Check your exposure

Who says so?

5 sources

cnnvd · enisa_euvd · fstec_bdu · cisco_csaf

EPSS · scored 2026-10-27

A vulnerability in the host input API daemon of Cisco Firepower Management Center (FMC) Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to improper certificate validation. An attacker could exploit this vulnerability by sending a crafted data stream to the host input daemon of the affected device. A successful exploit could allow the attacker to cause the host input daemon to restart. The attacker could use repeated attacks to cause the daemon to continuously reload, creating a DoS condition for the API.

remediations

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

A vendor fix is available.

FixedCisco Secure Firewall Management Center (FMC) 6.2.3.1 when installed on Cisco Secure Firewall Management Center (FMC) Appliancescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Management Center (FMC) 6.2.3.10 when installed on Cisco Secure Firewall Management Center (FMC) Appliancescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Management Center (FMC) 6.2.3.12 when installed on Cisco Secure Firewall Management Center (FMC) Appliancescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Management Center (FMC) 6.2.3.13 when installed on Cisco Secure Firewall Management Center (FMC) Appliancescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Management Center (FMC) 6.2.3.3 when installed on Cisco Secure Firewall Management Center (FMC) Appliancescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Management Center (FMC) 6.2.3.5 when installed on Cisco Secure Firewall Management Center (FMC) Appliancescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Management Center (FMC) 6.2.3.8 when installed on Cisco Secure Firewall Management Center (FMC) Appliancescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Management Center (FMC) 6.2.3.9 when installed on Cisco Secure Firewall Management Center (FMC) Appliancescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Management Center (FMC) 6.4.0 when installed on Cisco Secure Firewall Management Center (FMC) Appliancescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Management Center (FMC) 6.4.0.1 when installed on Cisco Secure Firewall Management Center (FMC) Appliancescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Management Center (FMC) 6.4.0.3 when installed on Cisco Secure Firewall Management Center (FMC) Appliancescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Management Center (FMC) 6.4.0.5 when installed on Cisco Secure Firewall Management Center (FMC) Appliancescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Management Center (FMC) 6.4.0.6 when installed on Cisco Secure Firewall Management Center (FMC) Appliancescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Management Center (FMC) 6.4.0.7 when installed on Cisco Secure Firewall Management Center (FMC) Appliancescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Management Center (FMC) 6.6.0 when installed on Cisco Secure Firewall Management Center (FMC) Appliancescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Management Center (FMC) 6.6.0.1 when installed on Cisco Secure Firewall Management Center (FMC) Appliancescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Management Center (FMC) 6.6.1 when installed on Cisco Secure Firewall Management Center (FMC) Appliancescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com

cvss

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

5.3

010

base score 0–10 · higher = more severe · hover a vector to decode

v2.05mediumAV:N/AC:L/Au:N/C:N/I:N/A:Pprimary · NVD / NIST USexploitability 10 · impact 2.9

v3.15.3mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Lprimary · NVD / NIST USexploitability 3.9 · impact 1.4

v3.15.3mediumAV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Lsecondary · FSTEC (BDU) RU

v3.15.3mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Lsecondary · ENISA EU

v3.15.3mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Lsecondary · psirt@cisco.com USexploitability 3.9 · impact 1.4

v3.14.9mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L/E:Usecondary · CVSS-BT (t0sche)

v3.15.3mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Lsecondary · Cisco PSIRT US

ssvc

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

Exploitation: none · Automatable: yes · Technical Impact: partialcoordinatorcisa_ssvcUS

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-295USprimaryCWE-295US

affected products (20)

Products and version ranges known to be affected.

advisories (1)

Vendor and ecosystem advisories describing this.

cisco-sa-fmc-dos-3WymYWKhCisco Firepower Management Center Software Denial of Service Vulnerability2020-10-21csaf · cisco_csafUS
A vulnerability in the host input API daemon of Cisco Firepower Management Center (FMC) Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to improper certificate validation. An attacker could exploit this vulnerability by sending a crafted data stream to the host input daemon of the affected device. A successful exploit could allow the attacker to cause the host input daemon to restart. The attacker could use repeated attacks to cause the daemon to continuously reload, creating a DoS condition for the API. Cisco has released software updates to address this vulnerability. There are no workarounds that address this vulnerability.

also known as (4)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd fstec_bdu cisco_csaf nvd NVD CVE.org MITRE

published 2020-10-21modified 2026-06-17

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+1889 more

references (6)

External citations — patches, advisories, analysis.

scry

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