CVE-2017-15271

medium

Published 2017-11-15 · Modified 2026-05-13

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CVSS v3

5.9

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

CVSS v4 NEW

—

not yet in upstream

VIR risk

6.9

Description

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.

Predictions

Exploit likelihood

69%

Patch ETA

—

Heuristic predictions, AS-IS, for prioritization only.

Mitigations

No mitigations published for this CVE yet.

The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.

✚ Propose a mitigation on Community → Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here with source_tier=community-verified.

Exploits

Public proof-of-concept code below. AS-IS, for defenders and authorised testing only.

Exploit-DB

EDB-43144 dos windows

X41 D-Sec GmbH · 2017-11-14

PSFTPd Windows FTP Server 10.0.4 Build 729 - Log Injection / Use-After-Free

Source code queued for fetch — refresh in a moment.

Application impact

Vendor	Product	Versions	Fixed
psftp	psftpd	`10.0.4`

References

CWEs

CWE-416

Community-verified mitigations for this CVE will appear above when contributors publish them.

Verify integrity in audit chain (admin only). AS-IS.