CVE-2022-36071

SFTPGo is configurable SFTP server with optional HTTP/S, FTP/S and WebDAV support. SFTPGo WebAdmin and WebClient support login using TOTP (Time-based One Time Passwords) as a secondary authentication factor. Because TOTPs are often configured on mobile devices that can be lost, stolen or damaged, SFTPGo also supports recovery codes. These are a set of one time use codes that can be used instead of the TOTP. In SFTPGo versions from version 2.2.0 to 2.3.3 recovery codes can be generated before enabling two-factor authentication. An attacker who knows the user's password could potentially generate some recovery codes and then bypass two-factor authentication after it is enabled on the account at a later time. This issue has been fixed in version 2.3.4. Recovery codes can now only be generated after enabling two-factor authentication and are deleted after disabling it.

SFTPGo is configurable SFTP server with optional HTTP/S, FTP/S and WebDAV support. SFTPGo WebAdmin and WebClient support login using TOTP (Time-based One Time Passwords) as a secondary authentication factor. Because TOTPs are often configured on mobile devices that can be lost, stolen or damaged, SFTPGo also supports recovery codes. These are a set of one time use codes that can be used instead of the TOTP. In SFTPGo versions from version 2.2.0 to 2.3.3 recovery codes can be generated before enabling two-factor authentication. An attacker who knows the user's password could potentially generate some recovery codes and then bypass two-factor authentication after it is enabled on the account at a later time. This issue has been fixed in version 2.3.4. Recovery codes can now only be generated after enabling two-factor authentication and are deleted after disabling it.

SFTPGo vulnerable to recovery codes abuse in github.com/drakkan/sftpgo

### Impact SFTPGo WebAdmin and WebClient support login using TOTP (Time-based One Time Passwords) as a seconday authentication factor. Because TOTPs are often configured on mobile devices that can be lost, stolen or damaged, SFTPGo also supports recovery codes. These are a set of one time use codes that can be used instead of the TOTP. In SFTPGo versions from v2.2.0 to v2.3.3 recovery codes can be generated before enabling two-factor authentication. An attacker who knows the user's password could potentially generate some recovery codes and then bypass two-factor authentication after it is enabled on the account at a later time. ### Patches Fixed in v2.3.4. Recovery codes can now only be generated after enabling two-factor authentication and are deleted after disabling it. ### Workarounds Regenerate recovery codes after enabling two-factor authentication. ### References https://github.com/drakkan/sftpgo/issues/965

SFTPGo es un servidor SFTP configurable con soporte opcional HTTP/S, FTP/S y WebDAV. SFTPGo WebAdmin y WebClient admiten el inicio de sesión mediante TOTP (Time-based One Time Passwords) como factor de autenticación secundario. Debido a que los TOTPs son configurados a menudo en dispositivos móviles que pueden ser perdidos, robados o dañados, SFTPGo también soporta códigos de recuperación. Estos son un conjunto de códigos de un solo uso que pueden ser usados en lugar de la TOTP. En las versiones de SFTPGo desde la versión 2.2.0 hasta 2.3.3, los códigos de recuperación pueden generarse antes de habilitar la autenticación de dos factores. Un atacante que conozca la contraseña del usuario podría generar potencialmente algunos códigos de recuperación y luego omitir la autenticación de dos factores después de habilitarla en la cuenta en un momento posterior. Este problema ha sido corregido en versión 2.3.4. Los códigos de recuperación ahora sólo pueden generarse después de habilitar la autenticación de dos factores y sean eliminados después de deshabilitarla