Cisco Firepower 1000 Series SSL/TLS Denial of Service Vulnerability

Summary

CVE	CVE-2020-3283
State	PUBLISHED
Assigner	cisco
Source Priority	CVE Program / NVD first with legacy fallback
Published	2020-05-06 17:15:12 UTC
Updated	2026-08-11 19:33:44 UTC
Description	A vulnerability in the Secure Sockets Layer (SSL)/Transport Layer Security (TLS) handler of Cisco Firepower Threat Defense (FTD) Software when running on the Cisco Firepower 1000 Series platform could allow an unauthenticated, remote attacker to trigger a denial of service (DoS) condition on an affected device. The vulnerability is due to a communication error between internal functions. An attacker could exploit this vulnerability by sending a crafted SSL/TLS message to an affected device. A successful exploit could allow the attacker to cause a buffer underrun, which leads to a crash. The crash causes the affected device to reload.

Risk And Classification

Primary CVSS: v3.1 8.6 HIGH from [email protected]

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

EPSS: 0.019560000 probability, percentile 0.784540000 (date 2026-08-12)

Problem Types: CWE-119 | CWE-787 | CWE-119 CWE-119

Version	Source	Type	Score	Severity	Vector
3.1	[email protected]	Primary	8.6	HIGH	`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H`
3.0	[email protected]	Secondary	8.6	HIGH	`CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H`
3.0	CNA	DECLARED	8.6	HIGH	`CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H`
2.0	[email protected]	Primary	5		`AV:N/AC:L/Au:N/C:N/I:N/A:P`

CVSS v3.1 Breakdown

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Changed

Confidentiality

None

Integrity

None

Availability

High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

CVSS v3.0 Breakdown

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Changed

Confidentiality

None

Integrity

None

Availability

High

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

CVSS v2.0 Breakdown

Access Vector

Network

Access Complexity

Low

Authentication

None

Confidentiality

None

Integrity

None

Availability

Partial

AV:N/AC:L/Au:N/C:N/I:N/A:P

NVD Known Affected Configurations (CPE 2.3)

Type	Vendor	Product	Version	Update	Edition	Language
Hardware	Cisco	Asa 5505	-	All	All	All
Operating System	Cisco	Asa 5505 Firmware	9.12\(2.12\)	All	All	All
Operating System	Cisco	Asa 5505 Firmware	9.13\(0.33\)	All	All	All
Hardware	Cisco	Asa 5510	-	All	All	All
Operating System	Cisco	Asa 5510 Firmware	9.12\(2.12\)	All	All	All
Operating System	Cisco	Asa 5510 Firmware	9.13\(0.33\)	All	All	All
Hardware	Cisco	Asa 5512-x	-	All	All	All
Operating System	Cisco	Asa 5512-x Firmware	9.12\(2.12\)	All	All	All
Operating System	Cisco	Asa 5512-x Firmware	9.13\(0.33\)	All	All	All
Hardware	Cisco	Asa 5515-x	-	All	All	All
Operating System	Cisco	Asa 5515-x Firmware	9.12\(2.12\)	All	All	All
Operating System	Cisco	Asa 5515-x Firmware	9.13\(0.33\)	All	All	All
Hardware	Cisco	Asa 5520	-	All	All	All
Operating System	Cisco	Asa 5520 Firmware	9.12\(2.12\)	All	All	All
Operating System	Cisco	Asa 5520 Firmware	9.13\(0.33\)	All	All	All
Hardware	Cisco	Asa 5525-x	-	All	All	All
Operating System	Cisco	Asa 5525-x Firmware	9.12\(2.12\)	All	All	All
Operating System	Cisco	Asa 5525-x Firmware	9.13\(0.33\)	All	All	All
Hardware	Cisco	Asa 5540	-	All	All	All
Operating System	Cisco	Asa 5540 Firmware	9.12\(2.12\)	All	All	All
Operating System	Cisco	Asa 5540 Firmware	9.13\(0.33\)	All	All	All
Hardware	Cisco	Asa 5545-x	-	All	All	All
Operating System	Cisco	Asa 5545-x Firmware	9.12\(2.12\)	All	All	All
Operating System	Cisco	Asa 5545-x Firmware	9.13\(0.33\)	All	All	All
Hardware	Cisco	Asa 5550	-	All	All	All
Operating System	Cisco	Asa 5550 Firmware	9.12\(2.12\)	All	All	All
Operating System	Cisco	Asa 5550 Firmware	9.13\(0.33\)	All	All	All
Hardware	Cisco	Asa 5555-x	-	All	All	All
Operating System	Cisco	Asa 5555-x Firmware	9.12\(2.12\)	All	All	All
Operating System	Cisco	Asa 5555-x Firmware	9.13\(0.33\)	All	All	All
Hardware	Cisco	Asa 5580	-	All	All	All
Operating System	Cisco	Asa 5580 Firmware	9.12\(2.12\)	All	All	All
Operating System	Cisco	Asa 5580 Firmware	9.13\(0.33\)	All	All	All
Hardware	Cisco	Asa 5585-x	-	All	All	All
Operating System	Cisco	Asa 5585-x Firmware	9.12\(2.12\)	All	All	All
Operating System	Cisco	Asa 5585-x Firmware	9.13\(0.33\)	All	All	All
Hardware	Cisco	Firepower 1010	-	All	All	All
Hardware	Cisco	Firepower 1020	-	All	All	All
Hardware	Cisco	Firepower 1030	-	All	All	All
Hardware	Cisco	Firepower 1040	-	All	All	All
Application	Cisco	Secure Firewall Threat Defense	All	All	All	All

Vendor Declared Affected Products

Source	Vendor	Product	Version	Platforms
CNA	Cisco	Cisco Firepower Threat Defense Software	affected n/a	Not specified

References

Reference	Source	Link	Tags
Cisco Firepower 1000 Series SSL/TLS Denial of Service Vulnerability	af854a3a-2127-422b-91ae-364da2661108	tools.cisco.com	Vendor Advisory
CVE Program record	CVE.ORG	www.cve.org	canonical
NVD vulnerability detail	NVD	nvd.nist.gov	canonical, analysis

No vendor comments have been submitted for this CVE.

Additional Advisory Data

Exploits

CNA: The Cisco Product Security Incident Response Team (PSIRT) is not aware of any public announcements or malicious use of the vulnerability that is described in this advisory.

There are currently no legacy QID mappings associated with this CVE.