CVE-2021-43503: Laravel/laravel Remote Code Execution Vulnerability

CRITICAL
Advisory Identifier: GHSA-86r3-4gq8-xw8q
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CVSS 9.8
CWE-502
Published
Advisory Summary

CVE-2021-43503 is a CRITICAL (CVSS 9.8) remote code execution vulnerability (CWE-502: Deserialization of Untrusted Data) affecting Laravel/laravel libraries in the Packagist ecosystem. The issue involves remote code execution in laravel. Remediation is available in the latest vendor maintenance releases.

CVE-2021-43503 at a Glance

CVE Identifier CVE-2021-43503
GHSA Identifier GHSA-86r3-4gq8-xw8q
Severity CRITICAL
CVSS v3.1 Base Score 9.8
CWE Classification CWE-502: Deserialization of Untrusted Data
Affected Product Laravel/laravel
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-2021-43503

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

laravel/laravel fixed: Latest secure release 
Upgrade laravel/laravel to Latest secure release
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 laravel/laravel

How to Check if You Are Affected

To determine whether your application is affected by CVE-2021-43503, inspect your project dependencies for Laravel/laravel:

inspect dependencies for laravel/laravel

Analyze the terminal output to locate any version of Laravel/laravel in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than the patched release), 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-502: Deserialization of Untrusted Data, where the product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid. In Laravel/laravel, 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

## Withdrawn This advisory has been withdrawn because it is not a security issue and the CVE has been revoked. ## Original Description A Remote Code Execution (RCE) vulnerability exists in h laravel 5.8.38 via an unserialize pop chain in (1) __destruct in \Routing\PendingResourceRegistration.php, (2) __cal in Queue\Capsule\Manager.php, and (3) __invoke in mockery\library\Mockery\ClosureWrapper.php.

CVE-2021-43503 Affected Laravel/laravel Versions

1 component(s)
Product / Package Ecosystem Affected Versions Fixed Version
laravel/laravel
 Packagist
≤ 5.8.38

References

NVD — CVE-2021-43503 NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-43503
Laravel/laravel Source Repository REPOSITORY
https://github.com/1nhann/vulns/issues/1#issuecomment-1213126338
Laravel/laravel Source Repository REPOSITORY
https://github.com/guoyanan1g/Laravel-vul/issues/2#issue-1045655892

Frequently Asked Questions

What is CVE-2021-43503?
CVE-2021-43503 is a security vulnerability in Laravel/laravel involving Remote Code Execution in Laravel under CWE-502: Deserialization of Untrusted Data.
Which Laravel/laravel versions are affected?
Affected versions include releases prior to current release patches across affected packages: laravel/laravel.
What version fixes CVE-2021-43503?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
Is laravel/laravel affected?
Yes, laravel/laravel is affected in releases prior to Latest secure release. Upgrade your dependency to Latest secure release or later.
What is the CVSS score of CVE-2021-43503?
CVE-2021-43503 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-2021-43503?
CVE-2021-43503 is classified under CWE-502: Deserialization of Untrusted Data (The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.).
How can I check Packagist dependencies for CVE-2021-43503?
Run the dependency tree command: 'inspect dependencies for laravel/laravel'. 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-86r3-4gq8-xw8q",
  "modified" : "2022-08-22T16:34:29Z",
  "published" : "2022-04-09T00:00:25Z",
  "withdrawn" : "2022-08-22T16:34:29Z",
  "aliases" : [ "CVE-2021-43503" ],
  "summary" : "Remote Code Execution in Laravel",
  "details" : "## Withdrawn\nThis advisory has been withdrawn because it is not a security issue and the CVE has been revoked.\n\n## Original Description\nA Remote Code Execution (RCE) vulnerability exists in h laravel 5.8.38 via an unserialize pop chain in (1) __destruct in \\Routing\\PendingResourceRegistration.php, (2) __cal in Queue\\Capsule\\Manager.php, and (3) __invoke in mockery\\library\\Mockery\\ClosureWrapper.php.",
  "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" : "laravel/laravel"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "last_affected" : "5.8.38"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2021-43503"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/1nhann/vulns/issues/1#issuecomment-1213126338"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/guoyanan1g/Laravel-vul/issues/2#issue-1045655892"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-502" ],
    "severity" : "CRITICAL",
    "github_reviewed" : true,
    "github_reviewed_at" : "2022-04-12T20:32:12Z",
    "nvd_published_at" : "2022-04-08T18:15:00Z"
  }
}