#VU60973 Path traversal in Serv-U FTP Server - CVE-2021-35250

Vulnerability identifier: #VU60973

Vulnerability risk: Medium

CVSSv4.0: 7.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:P/U:Green]

CVE-ID: CVE-2021-35250

CWE-ID: CWE-22

Exploitation vector: Network

Exploit availability: Yes

Vulnerable software:
Serv-U FTP Server
Server applications / File servers (FTP/HTTP)

Vendor: SolarWinds

Description

The vulnerability allows a remote attacker to perform directory traversal attacks.

The vulnerability exists due to input validation error when processing directory traversal sequences. A remote attacker can send a specially crafted HTTP request and read arbitrary files on the system.

Mitigation
Install update from vendor's website.

Vulnerable software versions

Serv-U FTP Server: 15.3

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External links
https://www.solarwinds.com/trust-center/security-advisories/cve-2021-35250

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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. However, proof of concept for this vulnerability is available.