Valhalla is an open source routing engine and accompanying libraries for use with OpenStreetMap data. In 3.7.0 and earlier, a POST request to /sources_to_targets containing an exclude_polygons ring formed by three collinear points can cause unbounded memory growth in the worker. The zero-area geometry, rather than the other request options, triggers processing in src/loki/polygon_search.cc until the process is terminated by the out-of-memory killer.
A single unauthenticated request can therefore stop a public-facing worker. Other endpoints that accept exclude_polygons, including /route, were not verified as affected. No fixed version is available as of this review.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Privileges Required
None
No privileges needed
User Interaction
None
No user interaction needed
Impact Assessment
Confidentiality
None
No data leak
Integrity
None
No data modification
Availability
High
Complete denial of service
CVSS Vector v3.1