CVE-2017-20166: Ecto Ecto Missing `is_nil` Requirement Vulnerability

CRITICAL
Advisory Identifier: GHSA-2xxx-fhc8-9qvq
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CVSS 9.8
Published
Advisory Summary

CVE-2017-20166 is a CRITICAL (CVSS 9.8) ecto missing `is_nil` requirement vulnerability (General Security Weakness) affecting Ecto libraries in the Hex ecosystem. The issue involves ecto missing `is_nil` requirement. Remediation is available by upgrading affected packages to version 2.2.1.

CVE-2017-20166 at a Glance

CVE Identifier CVE-2017-20166
GHSA Identifier GHSA-2xxx-fhc8-9qvq
Severity CRITICAL
CVSS v3.1 Base Score 9.8
CWE Classification General Security Weakness
Affected Product Ecto
Package Ecosystem Hex
Published Date
Last Updated

Security Impact

CVSS: 9.8

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

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

How to Fix CVE-2017-20166

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

ecto fixed: 2.2.1 
Upgrade ecto to 2.2.1
Verify Direct and Transitive Dependencies

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

inspect dependencies for ecto

How to Check if You Are Affected

To determine whether your application is affected by CVE-2017-20166, inspect your project dependencies for Ecto:

inspect dependencies for ecto

Analyze the terminal output to locate any version of Ecto in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 2.2.1), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under General Security Weakness. In Ecto, 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

Ecto will not raise on queries with non-explicit nil comparisons (ie if they aren't checked with `is_nil`).

CVE-2017-20166 Affected Ecto Versions

1 component(s)
Fixed Versions:
2.2.1
Product / Package Ecosystem Affected Versions Fixed Version
ecto
 Hex
≥ 2.2.0
< 2.2.1
All 1 versions
2.2.0
2.2.1

References

NVD — CVE-2017-20166 NVD
https://nvd.nist.gov/vuln/detail/CVE-2017-20166
Ecto Source Repository REPOSITORY
https://github.com/elixir-ecto/ecto/pull/2125
Security Fix Commit FIX COMMIT
https://github.com/elixir-ecto/ecto/commit/db55b0cba6525c24ebddc88ef9ae0c1c00620250
Ecto Source Repository REPOSITORY
https://github.com/elixir-ecto/ecto
groups.google.com/forum/ WEB
https://groups.google.com/forum/#!topic/elixir-ecto/0m4NPfg_MMU

Frequently Asked Questions

What is CVE-2017-20166?
CVE-2017-20166 is a security vulnerability in Ecto involving Ecto missing `is_nil` requirement under General Security Weakness.
Which Ecto versions are affected?
Affected versions include releases prior to 2.2.1 across affected packages: ecto.
What version fixes CVE-2017-20166?
Upgrading to 2.2.1 (or the latest patched release for your respective branch) resolves the vulnerability.
Is ecto affected?
Yes, ecto is affected in releases prior to 2.2.1. Upgrade your dependency to 2.2.1 or later.
What is the CVSS score of CVE-2017-20166?
CVE-2017-20166 has a CVSS v3.1 base score of 9.8 (CRITICAL) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
What CWE is associated with CVE-2017-20166?
CVE-2017-20166 is classified under General Security Weakness.
How can I check Hex dependencies for CVE-2017-20166?
Run the dependency tree command: 'inspect dependencies for ecto'. 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-2xxx-fhc8-9qvq",
  "modified" : "2026-01-22T20:38:59Z",
  "published" : "2022-04-12T19:42:45Z",
  "aliases" : [ "CVE-2017-20166" ],
  "summary" : "Ecto missing `is_nil` requirement",
  "details" : "Ecto will not raise on queries with non-explicit nil comparisons (ie if they aren't checked with `is_nil`).",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Hex",
      "name" : "ecto"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "2.2.0"
      }, {
        "fixed" : "2.2.1"
      } ]
    } ],
    "versions" : [ "2.2.0" ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2017-20166"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/elixir-ecto/ecto/pull/2125"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/elixir-ecto/ecto/commit/db55b0cba6525c24ebddc88ef9ae0c1c00620250"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/elixir-ecto/ecto"
  }, {
    "type" : "WEB",
    "url" : "https://groups.google.com/forum/#!topic/elixir-ecto/0m4NPfg_MMU"
  } ],
  "database_specific" : {
    "cwe_ids" : [ ],
    "severity" : "CRITICAL",
    "github_reviewed" : true,
    "github_reviewed_at" : "2022-04-12T19:42:45Z",
    "nvd_published_at" : null
  }
}