CVE-2017-15271 Explained : Impact and Mitigation

PSFTPd 10.0.4 Build 729 SFTP component is vulnerable to a use-after-free issue, allowing remote exploitation even before authentication. Attackers can trigger a DoS attack by sending a crafted SSH identification string.

Understanding CVE-2017-15271

PSFTPd 10.0.4 Build 729 is susceptible to a critical vulnerability that can be exploited remotely.

What is CVE-2017-15271?

The use-after-free vulnerability in the SFTP component of PSFTPd 10.0.4 Build 729 allows attackers to launch a DoS attack without authentication by manipulating the server's behavior.

The Impact of CVE-2017-15271

Attackers can exploit the vulnerability to trigger a DoS attack on the PSFTPd server.
The issue arises from a race condition in window message handling, leading to a use-after-free scenario.

Technical Details of CVE-2017-15271

PSFTPd 10.0.4 Build 729 vulnerability specifics.

Vulnerability Description

The vulnerability in the SFTP component of PSFTPd 10.0.4 Build 729 allows attackers to exploit a use-after-free issue, leading to a NULL pointer dereference.

Affected Systems and Versions

Product: PSFTPd 10.0.4 Build 729
Vendor: N/A
Version: N/A

Exploitation Mechanism

Attackers send a specifically crafted SSH identification string to trigger the vulnerability.
The server's failure to automatically restart enables the DoS attack.

Mitigation and Prevention

Protecting systems from CVE-2017-15271.

Immediate Steps to Take

Apply vendor-supplied patches or updates promptly.
Implement network-level protections to filter out malicious traffic.
Monitor network traffic for any signs of exploitation.

Long-Term Security Practices

Regularly update and patch software to address known vulnerabilities.
Conduct security assessments and penetration testing to identify and remediate weaknesses.

Patching and Updates

Check for patches or updates from PSFTPd to address the use-after-free vulnerability.