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Command injection in Parse Server through prototype pollution

Critical severity GitHub Reviewed Published Mar 11, 2022 in parse-community/parse-server • Updated Jan 27, 2023

Package

npm parse-server (npm)

Affected versions

< 4.10.7

Patched versions

4.10.7

Description

Impact

This is a Remote Code Execution (RCE) vulnerability in Parse Server. This vulnerability affects Parse Server in the default configuration with MongoDB. The main weakness that leads to RCE is the Prototype Pollution vulnerable code in the file DatabaseController.js, so it is likely to affect Postgres and any other database backend as well. This vulnerability has been confirmed on Linux (Ubuntu) and Windows.

Patches

Upgrade to Parse Server >=4.10.7. If you are using a prerelease version of Parse Server 5.0 (alpha, beta) we will publish a timely fix for these. However, as a general reminder we do not consider prerelease versions to be suitable for production deployment.

Note that as part of the fix a new security feature scans for sensitive keywords in request data to prevent JavaScript prototype pollution. If such a keyword is found, the request is rejected with HTTP response code 400 and Parse Error 105 (INVALID_KEY_NAME). By default these keywords are: {_bsontype: "Code"}, constructor, __proto__. If you are using any of these keywords in your request data, you can override the default keywords by setting the new Parse Server option requestKeywordDenylist to [] and specify your own keywords as needed.

Workarounds

Although the fix is more broad and includes several aspects of the vulnerability, a quick and targeted fix can be achieved by patching the MongoDB Node.js driver and disable BSON code execution. To apply the patch, add the following code to be executed before starting Parse Server, for example in index.js.

const BSON = require('bson');
 const internalDeserialize = BSON.prototype.deserialize;
 BSON.prototype.deserialize = (buffer, options = Object.create(null), ...others) => {
   if (options.constructor) {
     options = Object.assign(Object.create(null), options);
   }
   return internalDeserialize(buffer, options, ...others);
 };
 const internalDeserializeStream = BSON.prototype.deserializeStream;
 BSON.prototype.deserializeStream = (
   data,
   startIndex,
   numberOfDocuments,
   documents,
   docStartIndex,
   options = Object.create(null),
   ...others
 ) => {
   if (options.constructor) {
     options = Object.assign(Object.create(null), options);
   }
   return internalDeserializeStream(
     data,
     startIndex,
     numberOfDocuments,
     documents,
     docStartIndex,
     options,
     ...others
   );
 };

References

References

@mtrezza mtrezza published to parse-community/parse-server Mar 11, 2022
Published to the GitHub Advisory Database Mar 11, 2022
Reviewed Mar 11, 2022
Published by the National Vulnerability Database Mar 12, 2022
Last updated Jan 27, 2023

Severity

Critical

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Changed
Confidentiality
High
Integrity
High
Availability
High

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

EPSS score

9.725%
(95th percentile)

CVE ID

CVE-2022-24760

GHSA ID

GHSA-p6h4-93qp-jhcm

Credits

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