HOMEVULNERABILITIESCVE-2021-3331
CRITICAL

CVE-2021-3331

NVD-CWE-OtherPublished: January 27, 2021· Updated: Jun 17, 2026

9.8
CVSS v3.1

Official Description

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.)

NVD Source

Technical Analysis

CVE-2021-3331 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 9.8.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges Req.None
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityHigh
IntegrityHigh
AvailabilityHigh
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected Vendors & Products

winscp1 product(s)
winscp
Source: NVD CPE · 1 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

PATCHhttps://github.com/winscp/winscp/commit/faa96e8144e6925a380f94a97aa382c9427f688d
PATCHhttps://winscp.net/tracker/1943
PATCHhttps://github.com/winscp/winscp/commit/faa96e8144e6925a380f94a97aa382c9427f688d
PATCHhttps://winscp.net/tracker/1943
ADVISORYhttps://winscp.net/eng/docs/history#5.17.10
ADVISORYhttps://winscp.net/eng/docs/rawsettings
ADVISORYhttps://winscp.net/eng/docs/history#5.17.10
ADVISORYhttps://winscp.net/eng/docs/rawsettings

All References (8)

→
https://github.com/winscp/winscp/commit/faa96e8144e6925a380f94a97aa382c9427f688dPatch · Third Party Advisory
→
https://winscp.net/eng/docs/history#5.17.10Release Notes · Vendor Advisory
→
https://winscp.net/eng/docs/rawsettingsVendor Advisory
→
https://winscp.net/tracker/1943Patch · Vendor Advisory
→
https://github.com/winscp/winscp/commit/faa96e8144e6925a380f94a97aa382c9427f688dPatch · Third Party Advisory
→
https://winscp.net/eng/docs/history#5.17.10Release Notes · Vendor Advisory
→
https://winscp.net/eng/docs/rawsettingsVendor Advisory
→
https://winscp.net/tracker/1943Patch · Vendor Advisory

Quick Facts

CVE IDCVE-2021-3331
CVSS Score9.8 / 10
SeverityCRITICAL
WeaknessNVD-CWE-Other
CISA KEVNo
Affected1 vendor(s)
PublishedJan 27, 2021

Related CVEs (NVD-CWE-Other)

CVE-2002-0747
10.0
CVE-2002-1468
10.0
CVE-2001-1080
10.0
CVE-2022-4390
10.0
CVE-1999-1405
10.0
CVE-1999-0745
10.0

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2021-3331 in threat intel feeds
  • →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.
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