---
id: CVE-2021-3331
title: >-
  WinSCP before 5.17.10 allows remote attackers to execute arbitrary programs
  when the URL handler encounters a crafted URL that loads session settings
summary: >-
  WinSCP before 5.17.10 allows remote attackers to execute arbitrary programs
  when the URL handler encounters a crafted URL that loads session settings.
  (For example, this is exploitable in a default installation in which WinSCP is
  the han…
severity: critical
cvss: 9.8
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'
vendor: winscp
product: winscp
affected:
  - winscp < 5.17.10
patched:
  - winscp 5.17.10
published: '2021-01-27'
updated: '2026-10-08'
sourceUpdated: '2026-10-08T21:17:39.890'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2021-3331'
references:
  - url: >-
      https://github.com/winscp/winscp/commit/faa96e8144e6925a380f94a97aa382c9427f688d
    label: cve@mitre.org
  - url: 'https://winscp.net/eng/docs/history#5.17.10'
    label: cve@mitre.org
  - url: 'https://winscp.net/eng/docs/rawsettings'
    label: cve@mitre.org
  - url: 'https://winscp.net/tracker/1943'
    label: cve@mitre.org
  - url: >-
      https://github.com/winscp/winscp/commit/faa96e8144e6925a380f94a97aa382c9427f688d
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://winscp.net/eng/docs/history#5.17.10'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://winscp.net/eng/docs/rawsettings'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://winscp.net/tracker/1943'
    label: af854a3a-2127-422b-91ae-364da2661108
tags:
  - nvd
epss: 0.07611
epssPercentile: 0.94425
ingestedAt: '2026-10-08T22:11:53.725Z'
---

## Overview

WinSCP before 5.17.10 allows remote attackers to execute arbitrary programs when the URL handler encounters a crafted URL that loads session settings. (For example, this is exploitable in a default installation in which WinSCP is the handler for sftp:// URLs.)

## Affected

- `winscp < 5.17.10`

## Remediation

Upgrade past the affected range:

- `winscp 5.17.10`