CVE-2021-39173: Cachethq/cachet Remote Code Execution Vulnerability

HIGH
Advisory Identifier: GHSA-r67m-m8c7-jp83
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CVSS 8.8
CWE-704
Published
Advisory Summary

CVE-2021-39173 is a HIGH (CVSS 8.8) remote code execution vulnerability (CWE-704: Incorrect Type Conversion or Cast) affecting Cachethq/cachet libraries in the Packagist ecosystem. The issue involves cachet vulnerable to forced reinstall. Remediation is available by upgrading affected packages to version 2.5.1.

CVE-2021-39173 at a Glance

CVE Identifier CVE-2021-39173
GHSA Identifier GHSA-r67m-m8c7-jp83
Severity HIGH
CVSS v3.1 Base Score 8.8
CWE Classification CWE-704: Incorrect Type Conversion or Cast
Affected Product Cachethq/cachet
Package Ecosystem Packagist
Published Date
Last Updated

Security Impact

CVSS: 8.8

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

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 High (C:H)
Integrity High (I:H)
Availability High (A:H)

How to Fix CVE-2021-39173

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

cachethq/cachet fixed: 2.5.1 
Upgrade cachethq/cachet to 2.5.1
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 cachethq/cachet

How to Check if You Are Affected

To determine whether your application is affected by CVE-2021-39173, inspect your project dependencies for Cachethq/cachet:

inspect dependencies for cachethq/cachet

Analyze the terminal output to locate any version of Cachethq/cachet in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 2.5.1), 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 CWE-704: Incorrect Type Conversion or Cast, where the product does not correctly convert an object, resource, or structure from one type to a different type. In Cachethq/cachet, 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

### Impact Authenticated users, regardless of their privileges (_User_ or _Admin_), can trick Cachet and install the instance again, leading to arbitrary code execution on the server. ### Patches This issue was addressed by improving the middleware `ReadyForUse`, which now performs a stricter validation of the instance name. ### Workarounds Only allow trusted source IP addresses to access to the administration dashboard. ### References - https://blog.sonarsource.com/cachet-code-execution-via-laravel-configuration-injection ### For more information If you have any questions or comments about this advisory, you can contact: - The original reporters, by sending an email to vulnerability.research [at] sonarsource.com; - The maintainers, by opening an issue on this repository.

CVE-2021-39173 Affected Cachethq/cachet Versions

1 component(s)
Fixed Versions:
2.5.1
Product / Package Ecosystem Affected Versions Fixed Version
cachethq/cachet
 Packagist
< 2.5.1
2.5.1

References

GitHub Advisory / Wiki ADVISORY
https://github.com/fiveai/Cachet/security/advisories/GHSA-r67m-m8c7-jp83
NVD — CVE-2021-39173 NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-39173
blog.sonarsource.com/cachet-code-executi... WEB
https://blog.sonarsource.com/cachet-code-execution-via-laravel-configuration-injection
Cachethq/cachet Source Repository REPOSITORY
https://github.com/fiveai/Cachet
Cachethq/cachet Release RELEASE
https://github.com/fiveai/Cachet/releases/tag/v2.5.1

Frequently Asked Questions

What is CVE-2021-39173?
CVE-2021-39173 is a security vulnerability in Cachethq/cachet involving Cachet vulnerable to forced reinstall under CWE-704: Incorrect Type Conversion or Cast.
Which Cachethq/cachet versions are affected?
Affected versions include releases prior to 2.5.1 across affected packages: cachethq/cachet.
What version fixes CVE-2021-39173?
Upgrading to 2.5.1 (or the latest patched release for your respective branch) resolves the vulnerability.
Is cachethq/cachet affected?
Yes, cachethq/cachet is affected in releases prior to 2.5.1. Upgrade your dependency to 2.5.1 or later.
What is the CVSS score of CVE-2021-39173?
CVE-2021-39173 has a CVSS v3.1 base score of 8.8 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
What CWE is associated with CVE-2021-39173?
CVE-2021-39173 is classified under CWE-704: Incorrect Type Conversion or Cast (The product does not correctly convert an object, resource, or structure from one type to a different type.).
How can I check Packagist dependencies for CVE-2021-39173?
Run the dependency tree command: 'inspect dependencies for cachethq/cachet'. 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-r67m-m8c7-jp83",
  "modified" : "2022-08-16T18:40:56Z",
  "published" : "2021-08-30T16:11:33Z",
  "aliases" : [ "CVE-2021-39173" ],
  "summary" : "Cachet vulnerable to forced reinstall",
  "details" : "### Impact\n\nAuthenticated users, regardless of their privileges (_User_ or _Admin_), can trick Cachet and install the instance again, leading to arbitrary code execution on the server.\n\n### Patches\n\nThis issue was addressed by improving the middleware `ReadyForUse`, which now performs a stricter validation of the instance name. \n\n### Workarounds\n\nOnly allow trusted source IP addresses to access to the administration dashboard.\n\n### References\n\n- https://blog.sonarsource.com/cachet-code-execution-via-laravel-configuration-injection\n\n### For more information\n\nIf you have any questions or comments about this advisory, you can contact:\n- The original reporters, by sending an email to vulnerability.research [at] sonarsource.com;\n- The maintainers, by opening an issue on this repository.\n",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "cachethq/cachet"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "2.5.1"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/fiveai/Cachet/security/advisories/GHSA-r67m-m8c7-jp83"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2021-39173"
  }, {
    "type" : "WEB",
    "url" : "https://blog.sonarsource.com/cachet-code-execution-via-laravel-configuration-injection"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/fiveai/Cachet"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/fiveai/Cachet/releases/tag/v2.5.1"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-704" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2021-08-27T23:34:37Z",
    "nvd_published_at" : "2021-08-27T23:15:00Z"
  }
}