What is the CVSS score of CVE-2017-15271?

CVE-2017-15271 has a CVSS 3.0 base score of 5.9 (Medium). CVSS vector: CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H. EPSS exploitation probability: 19.3%.

Is there a public PoC exploit available for CVE-2017-15271?

Yes, a public proof-of-concept exploit is available for CVE-2017-15271. Prioritise patching immediately. EPSS: 19.3%.

Psftpd CVE-2017-15271

MEDIUM

Use After Free (CWE-416)

2017-11-15 cve@mitre.org

Denial Of Service Memory Corruption Use After Free Psftpd

5.9

CVSS 3.0 · NVD

Severity by source

NVD PRIMARY

5.9 MEDIUM

AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

Attack Vector

Network

Attack Complexity

High

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

Lifecycle Timeline

CVE Published

Nov 15, 2017 - 16:29 cve.org

MEDIUM 5.9

DescriptionCVE.org

A use-after-free issue could be triggered remotely in the SFTP component of PSFTPd 10.0.4 Build 729. This issue could be triggered prior to authentication. The PSFTPd server did not automatically restart, which enabled attackers to perform a very effective DoS attack against this service. By sending a crafted SSH identification / version string to the server, a NULL pointer dereference could be caused, apparently because of a race condition in the window message handling, performing the cleanup for invalid connections. This incorrect cleanup code has a use-after-free.

AnalysisAI

A use-after-free issue could be triggered remotely in the SFTP component of PSFTPd 10.0.4 Build 729. Rated medium severity (CVSS 5.9), this vulnerability is remotely exploitable, no authentication required. Public exploit code available and EPSS exploitation probability 19.3%.

Technical ContextAI

This vulnerability is classified as Use After Free (CWE-416), which allows attackers to access freed memory to execute arbitrary code or crash the application. A use-after-free issue could be triggered remotely in the SFTP component of PSFTPd 10.0.4 Build 729. This issue could be triggered prior to authentication. The PSFTPd server did not automatically restart, which enabled attackers to perform a very effective DoS attack against this service. By sending a crafted SSH identification / version string to the server, a NULL pointer dereference could be caused, apparently because of a race condition in the window message handling, performing the cleanup for invalid connections. This incorrect cleanup code has a use-after-free. Affected products include: Psftp Psftpd.

RemediationAI

No vendor patch is available at time of analysis. Monitor vendor advisories for updates. Use smart pointers or garbage-collected languages. Set pointers to NULL after freeing. Enable memory sanitizers.