Skip to content

C#: Fix a URL redirection from remote source false positive #14953

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
michaelnebel merged 6 commits into from
Dec 5, 2023
Merged

C#: Fix a URL redirection from remote source false positive #14953

Show file tree
Hide file tree
Changes from 1 commit
Commits
Show all changes
6 commits
Select commit Hold shift + click to select a range
66b456d
C#: Fix a URL redirection from remote source false positive
rpmrmartin Nov 29, 2023
6807fd1
C#: Add some stubs, a testcase and update the expected output without…
michaelnebel Dec 4, 2023
d160890
C#: Re-factor to avoid multiple explicit casts.
michaelnebel Dec 4, 2023
b9833fc
C#: Updated expected test output.
michaelnebel Dec 4, 2023
2fc7e51
C#: Only include source code (and not stubs) in the remote flow sourc…
michaelnebel Dec 4, 2023
8dcdda6
C#: Address review comments.
michaelnebel Dec 5, 2023
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
Next Next commit
C#: Fix a URL redirection from remote source false positive 
When guarding the redirect with `HttpRequestBase.IsUrlLocalToHost()`
  • Loading branch information
@rpmrmartin
rpmrmartin committed Nov 29, 2023
commit 66b456d3c642c6d23dd9665d1f339a0b63349ad1
12 changes: 9 additions & 3 deletions csharp/ql/lib/semmle/code/csharp/security/dataflow/UrlRedirectQuery.qll
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -116,13 +116,19 @@ class HttpServerTransferSink extends Sink {
}

private predicate isLocalUrlSanitizer(Guard g, Expr e, AbstractValue v) {
g.(MethodCall).getTarget().hasName("IsLocalUrl") and
e = g.(MethodCall).getArgument(0) and
(
g.(MethodCall).getTarget().hasName("IsLocalUrl") and
e = g.(MethodCall).getArgument(0)
or
g.(MethodCall).getTarget().hasName("IsUrlLocalToHost") and
e = g.(MethodCall).getArgument(1)
) and
v.(AbstractValues::BooleanValue).getValue() = true
}

/**
* A URL argument to a call to `UrlHelper.isLocalUrl()` that is a sanitizer for URL redirects.
* A URL argument to a call to `UrlHelper.IsLocalUrl()` or `HttpRequestBase.IsUrlLocalToHost()` that
* is a sanitizer for URL redirects.
*/
class LocalUrlSanitizer extends Sanitizer {
LocalUrlSanitizer() { this = DataFlow::BarrierGuard<isLocalUrlSanitizer/3>::getABarrierNode() }
Expand Down
4 changes: 4 additions & 0 deletions csharp/ql/src/change-notes/2023-11-29-url-redirect-false-positive.md
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,4 @@
---
category: minorAnalysis
---
* Fixed a URL redirection from remote source false positive when guarding a redirect with `HttpRequestBase.IsUrlLocalToHost()`