Description
copyparty is a portable file server. Prior to 1.20.19, FTP upload path handling does not confine destinations to configured copyparty volumes. When FTP or FTPS is explicitly enabled, a low-privileged authenticated user can submit traversal paths during upload to create a new file outside configured volumes wherever the copyparty process has write permission. The attacker cannot read or overwrite files, the output name receives a randomized suffix, and copyparty does not execute the file; however, unrelated software on the same host could process the newly created file. This issue is fixed in version 1.20.19.
References6
- github.com/9001/copyparty/commit/b331bb1c8c8cc306b91e4d94221969…
- github.com/9001/copyparty/releases/tag/v1.20.19
- github.com/9001/copyparty/security/advisories/GHSA-phv8-wgjp-g4…
- github.com/9001/copyparty/security/advisories/GHSA-phv8-wgjp-g4…
- github.com/9001/copyparty/security/advisories/GHSA-phv8-wgjp-g4…
- github.com/9001/copyparty/security/advisories/GHSA-phv8-wgjp-g4…
Metrics
- CVSS 4.0
-
5.3
MEDIUM
Score source: CNA
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:L/VA:N/SC:H/SI:H/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - EPSS — exploit probability
- 0% percentile: 25 · as of 11 November 2026
- CWE
- CWE-22
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.