CVE-2019-15256 Explained : Impact and Mitigation
Learn about CVE-2019-15256, a high-severity vulnerability in Cisco ASA Software and FTD Software IKEv1 functionality, allowing remote attackers to trigger a denial of service condition. Find mitigation steps and patching recommendations here.
A vulnerability in the Internet Key Exchange version 1 (IKEv1) feature of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to trigger a reload of an affected device, resulting in a denial of service (DoS) condition.
Understanding CVE-2019-15256
This CVE involves a flaw in the IKEv1 functionality of Cisco ASA Software and FTD Software, potentially leading to a DoS situation.
What is CVE-2019-15256?
The vulnerability stems from inadequate handling of system memory, allowing an attacker to send malicious IKEv1 traffic to exhaust system memory resources and force a device reload.
The Impact of CVE-2019-15256
- CVSS Base Score: 8.6 (High Severity)
- Attack Vector: Network
- Availability Impact: High
- Attack Complexity: Low
- The vulnerability could lead to a denial of service situation without requiring valid credentials from the attacker.
Technical Details of CVE-2019-15256
This section provides detailed technical information about the vulnerability.
Vulnerability Description
The flaw in IKEv1 functionality allows an unauthorized remote attacker to initiate a device reload by exploiting system memory handling.
Affected Systems and Versions
- Affected Product: Cisco Adaptive Security Appliance (ASA) Software
- Vendor: Cisco
- Affected Version: Unspecified
Exploitation Mechanism
- Attacker sends malicious IKEv1 traffic to the affected device
- Attacker does not need valid credentials to authenticate the VPN session
- Attacker's source address does not need to match a peer statement in the crypto map
Mitigation and Prevention
Protecting systems from CVE-2019-15256 requires immediate actions and long-term security practices.
Immediate Steps to Take
- Apply vendor-recommended patches and updates promptly
- Monitor network traffic for any suspicious IKEv1 activities
- Implement network segmentation to limit the impact of potential attacks
Long-Term Security Practices
- Regularly update and patch all software and firmware
- Conduct security assessments and penetration testing to identify vulnerabilities
- Educate users and administrators on best security practices
Patching and Updates
- Cisco has released patches to address this vulnerability
- Regularly check for updates and apply them to ensure system security