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Path Traversal occurrences in Uftpd
There are multiple unauthenticated directory traversal vulnerabilities in different FTP commands in uftpd FTP server versions 2.7 to 2.10 due to improper implementation of a chroot jail in common.c's compose_abspath function that can be abused to read or write to arbitrary files on the filesystem, leak process memory, or potentially lead to remote code execution. (2020-12-18, CVE-2020-20277)
In uftpd before 2.11, it is possible for an unauthenticated user to perform a directory traversal attack using multiple different FTP commands and read and write to arbitrary locations on the filesystem due to the lack of a well-written chroot jail in compose_abspath(). This has been fixed in version 2.11 (2020-01-22, CVE-2020-5221)
Why Path Traversal can be dangerous
Relative Path Confusion means that your web server is configured to serve responses to ambiguous URLs. This configuration can possibly cause confusion about the correct relative path for the URL. It is also an issue of resources, such as images, styles etc., which are specified in the response using relative path, not the absolute URL.
If the web browser permits to parse "cross-content" response, the attacker may be able to fool the web browser into interpreting HTML into other content types, which can then lead to a cross site scripting attack (link do XSS).