Remote code execution in WinSCP

1) Code Injection

EUVDB-ID: #VU50281

Risk: High

CVSSv3.1: 8.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-3331

CWE-ID: CWE-94 - Improper Control of Generation of Code ('Code Injection')

Exploit availability: No

Description

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to improper input validation. A remote attacker can execute arbitrary code on the target system when the URL handler encounters a crafted URL that loads session settings.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

WinSCP: 5.17 - 5.17.9

External links

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

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.