Skip to main content

Severity by source

NVD PRIMARY
7.5 HIGH
AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

Lifecycle Timeline

1
CVE Published
Oct 27, 2021 - 19:15 nvd
HIGH 7.5

DescriptionNVD

A vulnerability in the software-based SSL/TLS message handler of Cisco Adaptive Security Appliance (ASA) Software and Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause an affected device to reload, resulting in a denial of service (DoS) condition. This vulnerability is due to insufficient validation of SSL/TLS messages when the device performs software-based SSL/TLS decryption. 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 the affected device to reload, resulting in a DoS condition. Note: Datagram TLS (DTLS) messages cannot be used to exploit this vulnerability.

AnalysisAI

A vulnerability in the software-based SSL/TLS message handler of Cisco Adaptive Security Appliance (ASA) Software and Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.

Technical ContextAI

This vulnerability is classified as Buffer Overflow (CWE-119), which allows attackers to corrupt memory to execute arbitrary code or crash the application. A vulnerability in the software-based SSL/TLS message handler of Cisco Adaptive Security Appliance (ASA) Software and Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause an affected device to reload, resulting in a denial of service (DoS) condition. This vulnerability is due to insufficient validation of SSL/TLS messages when the device performs software-based SSL/TLS decryption. 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 the affected device to reload, resulting in a DoS condition. Note: Datagram TLS (DTLS) messages cannot be used to exploit this vulnerability. Affected products include: Cisco Firepower Threat Defense, Cisco Adaptive Security Appliance Software, Cisco Asa 5512-X Firmware, Cisco Asa 5505 Firmware, Cisco Asa 5515-X Firmware.

RemediationAI

No vendor patch is available at time of analysis. Monitor vendor advisories for updates. Use memory-safe languages or bounds-checking. Enable ASLR, DEP/NX, stack canaries. Use safe string functions.

CVE-2021-44228 CRITICAL POC
10.0 Dec 10

Apache Log4j2 contains a critical JNDI injection vulnerability known as 'Log4Shell' that allows unauthenticated remote c

CVE-2020-3452 HIGH POC
7.5 Jul 22

A vulnerability in the web services interface of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Th

CVE-2018-0296 HIGH POC
7.5 Jun 07

A vulnerability in the web interface of the Cisco Adaptive Security Appliance (ASA) could allow an unauthenticated, remo

CVE-2023-44487 HIGH POC
7.5 Oct 10

Denial of service against HTTP/2 server implementations allows remote unauthenticated attackers to exhaust server resour

CVE-2020-3580 MEDIUM POC
6.1 Oct 21

Multiple vulnerabilities in the web services interface of Cisco Adaptive Security Appliance (ASA) Software and Cisco Fir

CVE-2025-20362 HIGH POC
8.6 Sep 25

Unauthenticated remote access to restricted VPN web server endpoints in Cisco Secure ASA and Firepower Threat Defense (F

CVE-2020-3187 CRITICAL POC
9.1 May 06

A vulnerability in the web services interface of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Th

CVE-2020-3259 HIGH
7.5 May 06

A vulnerability in the web services interface of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Th

CVE-2018-0101 CRITICAL POC
10.0 Jan 29

A vulnerability in the Secure Sockets Layer (SSL) VPN functionality of the Cisco Adaptive Security Appliance (ASA) Softw

CVE-2024-20353 HIGH POC
8.6 Apr 24

Cisco ASA and FTD management and VPN web servers contain a vulnerability causing device reload through incomplete error

CVE-2025-20333 CRITICAL
9.9 Sep 25

A vulnerability in the VPN web server of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secu

CVE-2023-20269 CRITICAL
9.1 Sep 06

A vulnerability in the remote access VPN feature of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower

Share

CVE-2021-34783 vulnerability details – vuln.today

This site uses cookies essential for authentication and security. No tracking or analytics cookies are used. Privacy Policy