patrickjuchli basic-ftp up to 5.2.0 path crlf injection

Summaryinfo

A vulnerability classified as problematic has been found in patrickjuchli basic-ftp up to 5.2.0. This issue affects the function cd/remove/rename/uploadFrom/downloadTo/list/removeDir. This manipulation of the argument path causes crlf injection. This vulnerability is registered as CVE-2026-39983. Remote exploitation of the attack is possible. No exploit is available. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability classified as critical was found in patrickjuchli basic-ftp up to 5.2.0. Affected by this vulnerability is the function cd/remove/rename/uploadFrom/downloadTo/list/removeDir. The manipulation of the argument path with an unknown input leads to a crlf injection vulnerability. The CWE definition for the vulnerability is CWE-93. The product uses CRLF (carriage return line feeds) as a special element, e.g. to separate lines or records, but it does not neutralize or incorrectly neutralizes CRLF sequences from inputs. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

basic-ftp is an FTP client for Node.js. Prior to 5.2.1, basic-ftp allows FTP command injection via CRLF sequences (\r\n) in file path parameters passed to high-level path APIs such as cd(), remove(), rename(), uploadFrom(), downloadTo(), list(), and removeDir(). The library's protectWhitespace() helper only handles leading spaces and returns other paths unchanged, while FtpContext.send() writes the resulting command string directly to the control socket with \r\n appended. This lets attacker-controlled path strings split one intended FTP command into multiple commands. This vulnerability is fixed in 5.2.1.

It is possible to read the advisory at github.com. This vulnerability is known as CVE-2026-39983 since 04/08/2026. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. Technical details of the vulnerability are known, but there is no available exploit.

Upgrading to version 5.2.1 eliminates this vulnerability.

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Productinfo

Vendor

• patrickjuchli

Name

• basic-ftp

Version

• 5.0
• 5.1
• 5.2.0

Website

• Product: https://github.com/patrickjuchli/basic-ftp/

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