CVE-2021-34783
HighCVSS 8.6Exploitation Probability (EPSS)
Elevated risk73th percentile - higher than 73% of all known CVEs
Summary
A vulnerability in the software-based SSL/TLS message handler of Cisco ASA and FTD Software could allow an unauthenticated, remote attacker to reload the device, causing a denial of service (DoS). The issue is due to insufficient validation of SSL/TLS messages during software-based decryption. Exploitation involves sending a crafted SSL/TLS message.
Risk Assessment
Exploitation could cause device reload, leading to service unavailability and potential operational downtime.
Recommendation
Apply the latest software updates from Cisco and monitor security advisories for patches.
Other vulnerabilities in Cisco ASA Software
See all- CVE-2016-6432High
A vulnerability in the Identity Firewall feature of Cisco ASA Software before version 9.6(2.1) could allow an unauthenticated, remote attacker to cause a reload of the affected system or to remotely execute code. The issue is due to a buffer overflow in the affected code area.
- CVE-2016-6431High
A vulnerability in the local Certificate Authority (CA) feature of Cisco ASA Software before version 9.6(1.5) could allow an unauthenticated, remote attacker to cause a reload of the affected system. The issue is due to improper handling of crafted packets during the enrollment operation.
- CVE-2014-3392High
The Clientless SSL VPN portal in Cisco ASA Software before version 8.2(5.51), 8.3(2.42), 8.4(7.23), 8.6(1.15), 9.0(4.24), 9.1(5.12), 9.2(2.8), and 9.3(1.1) allows remote attackers to obtain sensitive information from process memory or modify memory contents via crafted parameters.
- CVE-2014-3389High
The VPN implementation in Cisco ASA Software versions before 7.2(5.15), 8.2(5.51), 8.3(2.42), 8.4(7.23), 8.6(1.15), 9.0(4.24), 9.1(5.12), 9.2(2.6), and 9.3(1.1) does not properly implement a tunnel filter, allowing remote authenticated users to gain failover-unit access via crafted packets.
- CVE-2014-3388High
The DNS inspection engine in Cisco ASA Software 9.0 before 9.0(4.13), 9.1 before 9.1(5.7), and 9.2 before 9.2(2) allows remote attackers to cause a denial of service (device reload) via crafted DNS packets.
- CVE-2014-3387High
The SunRPC inspection engine in Cisco ASA Software before versions 7.2(5.14), 8.2(5.51), 8.3(2.42), 8.4(7.23), 8.5(1.21), 8.6(1.14), 8.7(1.13), 9.0(4.5), and 9.1(5.3) allows remote attackers to cause a denial of service (device reload) via crafted SunRPC packets.
- CVE-2014-3386High
The GPRS Tunneling Protocol (GTP) inspection engine in Cisco ASA Software before version 8.2(5.51), 8.4(7.15), 8.7(1.13), 9.0(4.8), and 9.1(5.1) allows remote attackers to cause a denial of service (device reload) via a crafted series of GTP packets.
- CVE-2014-3385High
A race condition in the Health and Performance Monitoring (HPM) for ASDM feature in Cisco ASA allows remote attackers to cause a denial of service by generating many half-open TCP connections simultaneously.
- CVE-2014-3384High
The IKEv2 implementation in Cisco ASA Software before versions 8.4(7.15), 8.6(1.14), 9.0(4.8), and 9.1(5.1) allows remote attackers to cause a denial of service by sending a crafted packet during tunnel creation.
- CVE-2014-3383High
The IKE implementation in the VPN component in Cisco ASA Software 9.1 before 9.1(5.1) allows remote attackers to cause a denial of service (device reload) via crafted UDP packets.
Original NVD description (English source)
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.