CVE-2017-18594 : Exploit Details and Defense Strategies
Learn about CVE-2017-18594, a denial of service vulnerability in Nmap 7.70 due to a double free action in the SSH connection process. Find mitigation steps and preventive measures here.
In Nmap version 7.70, a vulnerability exists in the file nse_libssh2.cc that can lead to a denial of service issue. This vulnerability is triggered by a double free action during an SSH connection failure, specifically when encountering a leading \n character in certain scripts.
Understanding CVE-2017-18594
This CVE identifier pertains to a specific vulnerability in Nmap version 7.70 that can result in a denial of service condition.
What is CVE-2017-18594?
The vulnerability in Nmap version 7.70, tracked under CVE-2017-18594, allows for a denial of service scenario due to a double free action when an SSH connection fails, notably when specific scripts contain a leading \n character.
The Impact of CVE-2017-18594
The vulnerability can be exploited to cause a denial of service, potentially disrupting the availability of the affected Nmap service.
Technical Details of CVE-2017-18594
This section provides more technical insights into the vulnerability.
Vulnerability Description
The issue arises in the nse_libssh2.cc file within Nmap 7.70, where a double free action occurs upon SSH connection failure, triggered by a leading \n character in certain scripts.
Affected Systems and Versions
- Product: Nmap
- Vendor: N/A
- Version: 7.70
Exploitation Mechanism
The vulnerability is exploited by inducing a failure in the SSH connection process, specifically by introducing a leading \n character in either the ssh-brute.nse or ssh-auth-methods.nse scripts.
Mitigation and Prevention
To address and prevent the exploitation of CVE-2017-18594, consider the following steps:
Immediate Steps to Take
- Update Nmap to a patched version that addresses the double free vulnerability.
- Monitor network traffic for any signs of exploitation.
Long-Term Security Practices
- Regularly update and patch software to mitigate known vulnerabilities.
- Implement network segmentation to limit the impact of potential attacks.
Patching and Updates
- Apply patches provided by Nmap to fix the double free issue and enhance the overall security posture of the system.