CVE-2020-5203: Bcosca/fatfree Fat-Free Framework Arbitrary Code Execution Vulnerability

CRITICAL
Advisory Identifier: GHSA-hpj2-4hfj-g233
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CVSS 9.8
CWE-74
Published
Advisory Summary

CVE-2020-5203 is a CRITICAL (CVSS 9.8) fat-free framework arbitrary code execution vulnerability (CWE-74: Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')) affecting Bcosca/fatfree libraries in the Packagist ecosystem. The issue involves fat-free framework arbitrary code execution. Remediation is available by upgrading affected packages to version 3.7.2.

CVE-2020-5203 at a Glance

CVE Identifier CVE-2020-5203
GHSA Identifier GHSA-hpj2-4hfj-g233
Severity CRITICAL
CVSS v3.1 Base Score 9.8
CWE Classification CWE-74: Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')
Affected Product Bcosca/fatfree
Package Ecosystem Packagist
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-2020-5203

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

bcosca/fatfree fixed: 3.7.2 
Upgrade bcosca/fatfree to 3.7.2
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 bcosca/fatfree

How to Check if You Are Affected

To determine whether your application is affected by CVE-2020-5203, inspect your project dependencies for Bcosca/fatfree:

inspect dependencies for bcosca/fatfree

Analyze the terminal output to locate any version of Bcosca/fatfree in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 3.7.2), 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-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 Bcosca/fatfree, 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

In Fat-Free Framework 3.7.1, attackers can achieve arbitrary code execution if developers choose to pass user controlled input (e.g., `$_REQUEST`, `$_GET`, or `$_POST`) to the framework's Clear method.

CVE-2020-5203 Affected Bcosca/fatfree Versions

1 component(s)
Fixed Versions:
3.7.2
Product / Package Ecosystem Affected Versions Fixed Version
bcosca/fatfree
 Packagist
< 3.7.2
3.7.2

References

NVD — CVE-2020-5203 NVD
https://nvd.nist.gov/vuln/detail/CVE-2020-5203
Security Fix Commit FIX COMMIT
https://github.com/bcosca/fatfree-core/commit/dae95a0baf3963a9ef87c17cee52f78f77e21829
Bcosca/fatfree Source Repository REPOSITORY
https://github.com/bcosca/fatfree
Bcosca/fatfree Source Repository REPOSITORY
https://github.com/bcosca/fatfree/releases

Frequently Asked Questions

What is CVE-2020-5203?
CVE-2020-5203 is a security vulnerability in Bcosca/fatfree involving Fat-Free Framework arbitrary code execution under CWE-74: Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection').
Which Bcosca/fatfree versions are affected?
Affected versions include releases prior to 3.7.2 across affected packages: bcosca/fatfree.
What version fixes CVE-2020-5203?
Upgrading to 3.7.2 (or the latest patched release for your respective branch) resolves the vulnerability.
Is bcosca/fatfree affected?
Yes, bcosca/fatfree is affected in releases prior to 3.7.2. Upgrade your dependency to 3.7.2 or later.
What is the CVSS score of CVE-2020-5203?
CVE-2020-5203 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-2020-5203?
CVE-2020-5203 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 Packagist dependencies for CVE-2020-5203?
Run the dependency tree command: 'inspect dependencies for bcosca/fatfree'. 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-hpj2-4hfj-g233",
  "modified" : "2024-04-25T21:20:27Z",
  "published" : "2022-05-24T17:10:47Z",
  "aliases" : [ "CVE-2020-5203" ],
  "summary" : "Fat-Free Framework arbitrary code execution",
  "details" : "In Fat-Free Framework 3.7.1, attackers can achieve arbitrary code execution if developers choose to pass user controlled input (e.g., `$_REQUEST`, `$_GET`, or `$_POST`) to the framework's Clear method.",
  "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" : "Packagist",
      "name" : "bcosca/fatfree"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "3.7.2"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2020-5203"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/bcosca/fatfree-core/commit/dae95a0baf3963a9ef87c17cee52f78f77e21829"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/bcosca/fatfree"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/bcosca/fatfree/releases"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-74" ],
    "severity" : "CRITICAL",
    "github_reviewed" : true,
    "github_reviewed_at" : "2024-04-25T21:20:27Z",
    "nvd_published_at" : "2020-03-11T14:15:00Z"
  }
}