CVE-2019-1873 : Security Advisory and Response
Learn about CVE-2019-1873, a high-severity vulnerability in Cisco ASA and FTD Software allowing unauthorized attackers to trigger device reboots. Find mitigation steps and patching details here.
A flaw in the cryptographic driver of Cisco Adaptive Security Appliance (ASA) Software and Firepower Threat Defense (FTD) Software could allow unauthorized attackers to trigger an unexpected device reboot, potentially leading to a denial of service (DoS) situation.
Understanding CVE-2019-1873
This CVE involves a vulnerability in the cryptographic driver used by Cisco ASA and FTD Software, enabling attackers to cause a device reload through crafted TLS/SSL packets.
What is CVE-2019-1873?
The vulnerability stems from inadequate validation of packet headers for SSL/TLS ingress, allowing attackers to exploit the flaw by sending specially crafted packets to the device's interface.
The Impact of CVE-2019-1873
- Attack Complexity: Low
- Attack Vector: Network
- Availability Impact: High
- Base Score: 8.6 (High Severity)
- Scope: Changed
- Vector String: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
Technical Details of CVE-2019-1873
This section provides detailed technical information about the vulnerability.
Vulnerability Description
The vulnerability allows attackers to initiate an unexpected reboot of the targeted device by exploiting inadequate validation of SSL/TLS packet headers.
Affected Systems and Versions
- Affected Product: Cisco Adaptive Security Appliance (ASA) Software
- Vulnerable Versions: Below 9.4.4.36, 9.6.4.29, 9.8.4.3, 9.9.2.52, 9.10.1.22, 9.12.2
Exploitation Mechanism
- Attackers can exploit the vulnerability by sending crafted TLS/SSL packets to the device's interface.
- Successful exploitation can lead to a device reload and subsequent denial of service.
Mitigation and Prevention
Steps to address and prevent the CVE-2019-1873 vulnerability.
Immediate Steps to Take
- Apply vendor-provided patches or updates promptly.
- Monitor network traffic for any suspicious activity targeting the affected systems.
Long-Term Security Practices
- Regularly update and patch all software and firmware to mitigate potential vulnerabilities.
- Implement network segmentation and access controls to limit exposure to attacks.
Patching and Updates
- Cisco has released patches to address the vulnerability. Ensure timely application of these patches to secure the affected systems.