PathInjection.ql

/**
 * @name Uncontrolled data used in path expression
 * @description Accessing paths influenced by users can allow an attacker to access unexpected resources.
 * @kind path-problem
 * @problem.severity error
 * @sub-severity high
 * @precision high
 * @id py/path-injection
 * @tags correctness
 *       security
 *       external/owasp/owasp-a1
 *       external/cwe/cwe-022
 *       external/cwe/cwe-023
 *       external/cwe/cwe-036
 *       external/cwe/cwe-073
 *       external/cwe/cwe-099
 */

import python
import semmle.python.security.Paths

/* Sources */
import semmle.python.web.HttpRequest

/* Sinks */
import semmle.python.security.injection.Path

class PathInjectionConfiguration extends TaintTracking::Configuration {

    PathInjectionConfiguration() { this = "Path injection configuration" }

    override predicate isSource(TaintTracking::Source source) { source instanceof HttpRequestTaintSource }

    override predicate isSink(TaintTracking::Sink sink) { sink instanceof OpenNode }

    override predicate isSanitizer(Sanitizer sanitizer) {
        sanitizer instanceof PathSanitizer or
        sanitizer instanceof NormalizedPathSanitizer
    }

    override predicate isExtension(TaintTracking::Extension extension) {
        extension instanceof AbsPath
    }

}


from PathInjectionConfiguration config, TaintedPathSource src, TaintedPathSink sink
where config.hasFlowPath(src, sink)
select sink.getSink(), src, sink, "This path depends on $@.", src.getSource(), "a user-provided value"