CVE-2021-34783
8.6 · HIGHOverview
CVE-2021-34783 is a high-severity vulnerability affecting cisco secure_firewall_threat_defense. It was published on October 27, 2021 and has a CVSS 3.1 base score of 8.6 (HIGH).
This vulnerability has a CVSS 3.1 base score of 8.6, rated HIGH. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
Technical 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.
Remediation
Check the references section for vendor advisories and patches from cisco. Update secure_firewall_threat_defense to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
Affected Products
| Vendor | Product | Versions | Status |
|---|---|---|---|
| cisco | secure_firewall_threat_defense | >= 6.4.0, < 6.4.0.13 | Affected |
| cisco | adaptive_security_appliance_software | >= 9.8.0, < 9.8.4.40 | Affected |
Frequently Asked Questions
What is CVE-2021-34783?
CVE-2021-34783 is a high-severity vulnerability affecting cisco secure_firewall_threat_defense. It was published on October 27, 2021 and has a CVSS 3.1 base score of 8.6 (HIGH).
How severe is CVE-2021-34783?
This vulnerability has a CVSS 3.1 base score of 8.6, rated HIGH. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
How do I fix or remediate CVE-2021-34783?
Check the references section for vendor advisories and patches from cisco. Update secure_firewall_threat_defense to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2021-34783?
CyberStrike's AI-powered security agents can automatically detect CVE-2021-34783 across your infrastructure using autonomous pentesting, DAST scanning, and HackBrowser. The platform continuously monitors for known vulnerabilities and provides actionable remediation guidance prioritized by real-world exploitability.
How CyberStrike Helps
AI agents map your attack surface to find vulnerabilities like this one.
Automated penetration testing that runs continuously, not just quarterly.
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Browser-based exploitation validates findings with real proof-of-concept.
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