Alist is a file list program that supports multiple storages, powered by Gin and Solidjs. Prior to version 3.57.0, the application contains path traversal vulnerability in multiple file operation handlers. An authenticated attacker can bypass directory-level authorisation by injecting traversal sequences into filename components, enabling unauthorised file removal, movement and copying across user boundaries within the same storage mount. This issue has been patched in version 3.57.0.

Affected: Go: github.com/alist-org/alist/v3

### Summary The application contains a Path Traversal vulnerability (CWE-22) in multiple file operation handlers. An authenticated attacker can bypass directory-level authorisation by injecting traversal sequences into filename components, enabling unauthorised file removal, movement and copying across user boundaries within the same storage mount.

### Details The application contains a Path Traversal vulnerability (CWE-22) in multiple file operation handlers ([server/handles/fsmanage.go](https://github.com/AlistGo/alist/blob/main/server/handles/fsmanage.go), [server/handles/fsbatch.go](https://github.com/AlistGo/alist/blob/main/server/handles/fsbatch.go), etc.). Filename components in `req.Names`, `renameObject.SrcName`, and `renameObject.NewName` are directly concatenated with validated directories using `stdpath.Join()` or `fmt.Sprintf()`. This allows ".." sequences to bypass path restrictions, enabling users to access other users' files within the same storage mount and perform unauthorized actions such as deletion, renaming, or copying of files.

[FsRemove](https://github.com/AlistGo/alist/blob/b4d9beb49cba399842a54fcc33bc95a4a09b7bd4/server/handles/fsmanage.go#L253-L254): ~~~go func FsRemove(c *gin.Context) { // ... for _, name := range req.Names { err := fs.Remove(c, stdpath.Join(reqDir, name)) ~~~

[FsCopy](https://github.com/AlistGo/alist/blob/b4d9beb49cba399842a54fcc33bc95a4a09b7bd4/server/handles/fsmanage.go#L165-L166): ~~~go func FsCopy(c *gin.Context) { //…