CVE-2019-10795: Undefsafe Prototype Pollution Vulnerability

MODERATE
Advisory Identifier: GHSA-332q-7ff2-57h2
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CVSS 6.3
CWE-74
Published
Advisory Summary

CVE-2019-10795 is a MODERATE (CVSS 6.3) prototype pollution vulnerability (CWE-74: Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')) affecting Undefsafe libraries in the npm ecosystem. The issue involves prototype pollution in undefsafe. Remediation is available by upgrading affected packages to version 2.0.3.

CVE-2019-10795 at a Glance

CVE Identifier CVE-2019-10795
GHSA Identifier GHSA-332q-7ff2-57h2
Severity MODERATE
CVSS v3.1 Base Score 6.3
CWE Classification CWE-74: Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')
Affected Product Undefsafe
Package Ecosystem npm
Published Date
Last Updated

Security Impact

CVSS: 6.3

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:L/A:L).

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 Low (I:L)
Availability Low (A:L)

How to Fix CVE-2019-10795

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

undefsafe fixed: 2.0.3 
npm install undefsafe@2.0.3
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 undefsafe

How to Check if You Are Affected

To determine whether your Node.js application is affected by CVE-2019-10795, inspect your project dependencies using npm:

npm ls undefsafe

Analyze the terminal output to locate any version of Undefsafe in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 2.0.3), your application is affected.

Note: The npm ls undefsafe 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-74: Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection'), where the product constructs all or part of a command, data structure, or record using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify how it is parsed or interpreted when it is sent to a downstream component. In Undefsafe, 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

undefsafe before 2.0.3 is vulnerable to Prototype Pollution. The 'a' function could be tricked into adding or modifying properties of Object.prototype using a `__proto__` payload.

CVE-2019-10795 Affected Undefsafe Versions

1 component(s)
Fixed Versions:
2.0.3
Product / Package Ecosystem Affected Versions Fixed Version
undefsafe
npm/undefsafe
npm
< 2.0.3
2.0.3

References

NVD — CVE-2019-10795 NVD
https://nvd.nist.gov/vuln/detail/CVE-2019-10795
Security Fix Commit FIX COMMIT
https://github.com/remy/undefsafe/commit/f272681b3a50e2c4cbb6a8533795e1453382c822
Undefsafe Source Repository REPOSITORY
https://github.com/remy/undefsafe
snyk.io/vuln/snyk-js-undefs... WEB
https://snyk.io/vuln/SNYK-JS-UNDEFSAFE-548940

Frequently Asked Questions

What is CVE-2019-10795?
CVE-2019-10795 is a security vulnerability in Undefsafe involving Prototype Pollution in undefsafe under CWE-74: Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection').
Which Undefsafe versions are affected?
Affected versions include releases prior to 2.0.3 across affected packages: undefsafe.
What version fixes CVE-2019-10795?
Upgrading to 2.0.3 (or the latest patched release for your respective branch) resolves the vulnerability.
Is undefsafe affected?
Yes, undefsafe is affected in releases prior to 2.0.3. Upgrade your dependency to 2.0.3 or later.
What is the CVSS score of CVE-2019-10795?
CVE-2019-10795 has a CVSS v3.1 base score of 6.3 (MODERATE) with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L.
What CWE is associated with CVE-2019-10795?
CVE-2019-10795 is classified under CWE-74: Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection') (The product constructs all or part of a command, data structure, or record using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify how it is parsed or interpreted when it is sent to a downstream component.).
How can I check npm dependencies for CVE-2019-10795?
Run the dependency tree command: 'npm ls undefsafe'. 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-332q-7ff2-57h2",
  "modified" : "2022-02-24T18:21:34Z",
  "published" : "2022-02-09T22:34:01Z",
  "aliases" : [ "CVE-2019-10795" ],
  "summary" : "Prototype Pollution in undefsafe",
  "details" : "undefsafe before 2.0.3 is vulnerable to Prototype Pollution. The 'a' function could be tricked into adding or modifying properties of Object.prototype using a `__proto__` payload.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "undefsafe"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "2.0.3"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2019-10795"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/remy/undefsafe/commit/f272681b3a50e2c4cbb6a8533795e1453382c822"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/remy/undefsafe"
  }, {
    "type" : "WEB",
    "url" : "https://snyk.io/vuln/SNYK-JS-UNDEFSAFE-548940"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-74" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2021-04-07T21:18:46Z",
    "nvd_published_at" : "2020-02-18T16:15:00Z"
  }
}