Potential path traversal from request

Docs > Code Analysis > Static Analysis Rules > Potential path traversal from request

Metadata

ID: java-security/path-traversal-file-read

Language: Java

Severity: Error

Category: Security

Description

The filename of the file being opened comes from an input parameter. If an unfiltered parameter is passed to the API, any location on the filesystem can be read.

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Non-Compliant Code Examples

class MyClass {

    @GET
    @Path("/images/{image}")
    @Produces("images/*")
    public Response getImage(@javax.ws.rs.PathParam("image") String image) {
        File file = new File("resources/images/", image); //Weak point

        if (!file.exists()) {
            return Response.status(Status.NOT_FOUND).build();
        }

        return Response.ok().entity(new FileInputStream(file)).build();
    }

}

Compliant Code Examples

import org.apache.commons.io.FilenameUtils;

class MyClass {

    @GET
    @Path("/images/{image}")
    @Produces("images/*")
    public Response getImage(@javax.ws.rs.PathParam("image") String image) {
        File file = new File("resources/images/", FilenameUtils.getName(image)); //Fix

        if (!file.exists()) {
            return Response.status(Status.NOT_FOUND).build();
        }

        return Response.ok().entity(new FileInputStream(file)).build();
    }

    @GET
    @Path("/images/{image}")
    @Produces("images/*")
    public Response getImage(@javax.ws.rs.PathParam("image") String image) {
        File file = new File("resources/images/", image2); //Weak point

        if (!file.exists()) {
            return Response.status(Status.NOT_FOUND).build();
        }

        return Response.ok().entity(new FileInputStream(file)).build();
    }

}