CVE-2021-34783
high
Cisco CVSS v3 Base Score
8.6
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
EPSS Score
1.6%
Exploitation probability in 30 days
Top 27% most likely to be exploited
Attack Characteristics
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Confidentiality
None
Integrity
None
Availability
High
Published: October 27, 2021 (1775 days ago)
Last Modified: August 11, 2026
Vendor: Cisco
Source: NVD
Vulnerability Report
Generated by CyberWatcher
Description
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.
CWE
CWE-119Affected Products
cisco secure firewall threat defensecisco adaptive security appliance softwarecisco asa 5512-x firmwarecisco asa 5505 firmwarecisco asa 5515-x firmwarecisco asa 5525-x firmwarecisco asa 5545-x firmwarecisco asa 5555-x firmwarecisco asa 5580 firmwarecisco asa 5585-x firmware