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Fencer Vulns
medium 5.9

CVE-2017-15271 json

A use-after-free issue could be triggered remotely in the SFTP component of PSFTPd 10.0.4 Build 729.

published 2017-11-15 8 y ago modified 2026-06-17 4 mo ago also EUVD-2017-6731

cvss
5.9
version 3.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
8.7%
EPSS 8.7% chance of exploitation in 30 days, percentile 95%
public exploits
1
Exploit-DB

Summary

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.

Timeline

  1. First public exploit (EDB-43144)
  2. Published

Exploit prediction

8.74% chance of exploitation in the next 30 days, higher than 95% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • EDB-43144 PSFTPd Windows FTP Server 10.0.4 Build 729 - Log Injection / Use-After-Free dos, 2017-11-14

CVSS scores

assigned by version score vector
NVD 3.0 5.9 CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD 2.0 4.3 AV:N/AC:M/Au:N/C:N/I:N/A:P

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.