CVE-2021-3689: Yiisoft/yii2 dev Use Of Insufficiently Random Values Vulnerability

HIGH
Advisory Identifier: GHSA-hq3v-rg6f-6hx4
CVSS 7.5
CWE-330
Published
Advisory Summary

CVE-2021-3689 is a HIGH (CVSS 7.5) use of insufficiently random values vulnerability (CWE-330: Use of Insufficiently Random Values) affecting Yiisoft/yii2 dev libraries in the Packagist ecosystem. The issue involves use of insufficiently random values in yiisoft/yii2-dev. Remediation is available by upgrading affected packages to version 2.0.43.

CVE-2021-3689 at a Glance

CVE Identifier CVE-2021-3689
GHSA Identifier GHSA-hq3v-rg6f-6hx4
Severity HIGH
CVSS v3.1 Base Score 7.5
CWE Classification CWE-330: Use of Insufficiently Random Values
Affected Product Yiisoft/yii2 dev
Package Ecosystem Packagist
Published Date
Last Updated

Security Impact

CVSS: 7.5

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:N/I:H/A:N).

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 None (C:N)
Integrity High (I:H)
Availability None (A:N)

How to Fix CVE-2021-3689

To remediate this vulnerability, upgrade all affected Yiisoft/yii2 dev dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

yiisoft/yii2-dev fixed: 2.0.43
Upgrade yiisoft/yii2-dev to 2.0.43
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 yiisoft/yii2-dev

How to Check if You Are Affected

To determine whether your application is affected by CVE-2021-3689, inspect your project dependencies for Yiisoft/yii2 dev:

inspect dependencies for yiisoft/yii2-dev

Analyze the terminal output to locate any version of Yiisoft/yii2 dev in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 2.0.43), 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 CWE-330: Use of Insufficiently Random Values, where the product uses insufficiently random numbers or values in a security context that depends on unpredictable numbers. In Yiisoft/yii2 dev, 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

yii2 is vulnerable to Use of Predictable Algorithm in Random Number Generator

CVE-2021-3689 Affected Yiisoft/yii2 dev Versions

1 component(s)
Fixed Versions:
2.0.43
Product / Package Ecosystem Affected Versions Fixed Version
yiisoft/yii2-dev
Packagist
< 2.0.43
2.0.43

References

Frequently Asked Questions

What is CVE-2021-3689?
CVE-2021-3689 is a security vulnerability in Yiisoft/yii2 dev involving Use of Insufficiently Random Values in yiisoft/yii2-dev under CWE-330: Use of Insufficiently Random Values.
Which Yiisoft/yii2 dev versions are affected?
Affected versions include releases prior to 2.0.43 across affected packages: yiisoft/yii2-dev.
What version fixes CVE-2021-3689?
Upgrading to 2.0.43 (or the latest patched release for your respective branch) resolves the vulnerability.
Is yiisoft/yii2-dev affected?
Yes, yiisoft/yii2-dev is affected in releases prior to 2.0.43. Upgrade your dependency to 2.0.43 or later.
What is the CVSS score of CVE-2021-3689?
CVE-2021-3689 has a CVSS v3.1 base score of 7.5 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N.
What CWE is associated with CVE-2021-3689?
CVE-2021-3689 is classified under CWE-330: Use of Insufficiently Random Values (The product uses insufficiently random numbers or values in a security context that depends on unpredictable numbers.).
How can I check Packagist dependencies for CVE-2021-3689?
Run the dependency tree command: 'inspect dependencies for yiisoft/yii2-dev'. 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
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-hq3v-rg6f-6hx4",
  "modified" : "2021-08-30T20:28:40Z",
  "published" : "2021-09-01T18:35:34Z",
  "aliases" : [ "CVE-2021-3689" ],
  "summary" : "Use of Insufficiently Random Values in yiisoft/yii2-dev",
  "details" : "yii2 is vulnerable to Use of Predictable Algorithm in Random Number Generator",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "yiisoft/yii2-dev"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "2.0.43"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2021-3689"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/yiisoft/yii2/commit/13f27e4d920a05d53236139e8b07007acd046a46"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/yiisoft/yii2"
  }, {
    "type" : "WEB",
    "url" : "https://huntr.dev/bounties/50aad1d4-eb00-4573-b8a4-dbe38e2c229f"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-330" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2021-08-30T20:28:40Z",
    "nvd_published_at" : "2021-08-10T11:15:00Z"
  }
}