CVE-2020-15270: Parse server Receiving Subscription Objects With Deleted Vulnerability

MODERATE
Advisory Identifier: GHSA-2xm2-xj2q-qgpj
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CVSS 4.3
CWE-672
Published
Advisory Summary

CVE-2020-15270 is a MODERATE (CVSS 4.3) receiving subscription objects with deleted vulnerability (CWE-672: Operation on a Resource after Expiration or Release) affecting Parse server libraries in the npm ecosystem. The issue involves receiving subscription objects with deleted session. Remediation is available by upgrading affected packages to version 4.4.0.

CVE-2020-15270 at a Glance

CVE Identifier CVE-2020-15270
GHSA Identifier GHSA-2xm2-xj2q-qgpj
Severity MODERATE
CVSS v3.1 Base Score 4.3
CWE Classification CWE-672: Operation on a Resource after Expiration or Release
Affected Product Parse server
Package Ecosystem npm
Published Date
Last Updated

Security Impact

CVSS: 4.3

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required Low (PR:L)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality Low (C:L)
Integrity None (I:N)
Availability None (A:N)

How to Fix CVE-2020-15270

To remediate this vulnerability, upgrade all affected Parse server dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

parse-server fixed: 4.4.0 
npm install parse-server@4.4.0
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

npm ls parse-server

How to Check if You Are Affected

To determine whether your Node.js application is affected by CVE-2020-15270, inspect your project dependencies using npm:

npm ls parse-server

Analyze the terminal output to locate any version of Parse server in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 4.4.0), your application is affected.

Note: The npm ls parse-server command inspects dependencies declared in your package.json and lockfile; it does not perform automated runtime dynamic scanning.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-672: Operation on a Resource after Expiration or Release, where the product uses, accesses, or otherwise operates on a resource after that resource has been expired, released, or revoked. In Parse server, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

Original Message: Hi, I create objects with one client with an ACL of all users with a specific column value. Thats working so far. Then I deleted the session object from one user to look if he can receive subscription objects and he can receive them. The client with the deleted session cant create new objects, which Parse restricts right. The LiveQueryServer doesnt detect deleted sessions after the websocket connection was established. There should be a mechanism that checks in an specific interval if the session exists. I dont know if its true with expired sessions. Any solutions? Parse version: 4.3.0 Parse js SDK version: 2.17 Solution: Hi guys. I've found and fixed the problem. It happens because there are two caches in place for the session token: - at Parse Server level, which, according with the docs, should be changed via cacheTTL option and defaults to 5 seconds; - at Parse Live Query level, which, according with the docs, should be changed via liveQueryServerOptions.cacheTimeout and defaults to 30 days. But there are three problems: - cacheTTL has currently no effect over Live Query Server; - cacheTimeout also has currently no effect over Live Query Server; - cacheTimeout actually defaults to 1h. So, currently, if you wait 1 hour after the session token was invalidated, the clients using the old session token are not able to receive the events. What I did: - Added a test case for the problem; - Fixed cacheTTL for Live Query Server; - Fixed cacheTimeout for Live Query Server; - Changed the cacheTimeout to default 5s; - Changed the docs to reflect the actual 5s default for cacheTimeout.

CVE-2020-15270 Affected Parse server Versions

1 component(s)
Fixed Versions:
4.4.0
Product / Package Ecosystem Affected Versions Fixed Version
parse-server
npm/parse-server
npm
< 4.4.0
4.4.0

References

GitHub Advisory / Wiki ADVISORY
https://github.com/parse-community/parse-server/security/advisories/GHSA-2xm2-xj2q-qgpj
NVD — CVE-2020-15270 NVD
https://nvd.nist.gov/vuln/detail/CVE-2020-15270
Security Fix Commit FIX COMMIT
https://github.com/parse-community/parse-server/commit/78b59fb26b1c36e3cdbd42ba9fec025003267f58
Parse server Source Repository REPOSITORY
https://github.com/parse-community/parse-server

Frequently Asked Questions

What is CVE-2020-15270?
CVE-2020-15270 is a security vulnerability in Parse server involving receiving subscription objects with deleted session under CWE-672: Operation on a Resource after Expiration or Release.
Which Parse server versions are affected?
Affected versions include releases prior to 4.4.0 across affected packages: parse-server.
What version fixes CVE-2020-15270?
Upgrading to 4.4.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is parse-server affected?
Yes, parse-server is affected in releases prior to 4.4.0. Upgrade your dependency to 4.4.0 or later.
What is the CVSS score of CVE-2020-15270?
CVE-2020-15270 has a CVSS v3.1 base score of 4.3 (MODERATE) with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N.
What CWE is associated with CVE-2020-15270?
CVE-2020-15270 is classified under CWE-672: Operation on a Resource after Expiration or Release (The product uses, accesses, or otherwise operates on a resource after that resource has been expired, released, or revoked.).
How can I check npm dependencies for CVE-2020-15270?
Run the dependency tree command: 'npm ls parse-server'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-2xm2-xj2q-qgpj",
  "modified" : "2021-10-06T22:02:05Z",
  "published" : "2020-10-27T19:15:19Z",
  "aliases" : [ "CVE-2020-15270" ],
  "summary" : "receiving subscription objects with deleted session",
  "details" : "Original Message:\nHi,\n\nI create objects with one client with an ACL of all users with a specific column value. Thats working so far.\n\nThen I deleted the session object from one user to look if he can receive subscription objects and he can receive them.\nThe client with the deleted session cant create new objects, which Parse restricts right.\n\nThe LiveQueryServer doesnt detect deleted sessions after the websocket connection was established.\nThere should be a mechanism that checks in an specific interval if the session exists.\nI dont know if its true with expired sessions.\n\nAny solutions?\n\nParse version: 4.3.0\nParse js SDK version: 2.17\n\nSolution:\nHi guys.\n\nI've found and fixed the problem. It happens because there are two caches in place for the session token:\n\n- at Parse Server level, which, according with the docs, should be changed via cacheTTL option and defaults to 5 seconds;\n- at Parse Live Query level, which, according with the docs, should be changed via liveQueryServerOptions.cacheTimeout and defaults to 30 days.\n\nBut there are three problems:\n\n- cacheTTL has currently no effect over Live Query Server;\n- cacheTimeout also has currently no effect over Live Query Server;\n- cacheTimeout actually defaults to 1h.\n\nSo, currently, if you wait 1 hour after the session token was invalidated, the clients using the old session token are not able to receive the events.\n\nWhat I did:\n\n- Added a test case for the problem;\n- Fixed cacheTTL for Live Query Server;\n- Fixed cacheTimeout for Live Query Server;\n- Changed the cacheTimeout to default 5s;\n- Changed the docs to reflect the actual 5s default for cacheTimeout.\n\n",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "parse-server"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "4.4.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/parse-community/parse-server/security/advisories/GHSA-2xm2-xj2q-qgpj"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2020-15270"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/parse-community/parse-server/commit/78b59fb26b1c36e3cdbd42ba9fec025003267f58"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/parse-community/parse-server"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-672" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2020-10-22T21:12:08Z",
    "nvd_published_at" : "2020-10-22T22:15:00Z"
  }
}