CVE-2021-32697: Neos/form Form Validation Can Be Skipped Vulnerability

MODERATE
Advisory Identifier: GHSA-m5vx-8chx-qvmm
Share
CVSS 6.5
CWE-20
Published
Advisory Summary

CVE-2021-32697 is a MODERATE (CVSS 6.5) form validation can be skipped vulnerability (CWE-20: Improper Input Validation) affecting Neos/form libraries in the Packagist ecosystem. The issue involves form validation can be skipped. Remediation is available by upgrading affected packages to version 4.3.3, 5.0.9, 5.1.3.

CVE-2021-32697 at a Glance

CVE Identifier CVE-2021-32697
GHSA Identifier GHSA-m5vx-8chx-qvmm
Severity MODERATE
CVSS v3.1 Base Score 6.5
CWE Classification CWE-20: Improper Input Validation
Affected Product Neos/form
Package Ecosystem Packagist
Published Date
Last Updated

Security Impact

CVSS: 6.5

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:L/I:L/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 Low (C:L)
Integrity Low (I:L)
Availability None (A:N)

How to Fix CVE-2021-32697

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

neos/form fixed: 4.3.3 
Upgrade neos/form to 4.3.3
neos/form fixed: 5.0.9 
Upgrade neos/form to 5.0.9
neos/form fixed: 5.1.3 
Upgrade neos/form to 5.1.3
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 neos/form

How to Check if You Are Affected

To determine whether your application is affected by CVE-2021-32697, inspect your project dependencies for Neos/form:

inspect dependencies for neos/form

Analyze the terminal output to locate any version of Neos/form in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 4.3.3), 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-20: Improper Input Validation, where the product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly. In Neos/form, 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 By crafting a special `GET` request containing a valid form state, a form can be submitted without invoking any validators. We consider the severity _low_ because it is not possible to _change_ any form values since the form state is secured with an HMAC that is still verified. That means that this issue can only be exploited if Form Finishers cause side effects even if no form values have been sent. ### Patches https://github.com/neos/form/commit/69de4219b1f58157e2be6b05811463875d75c246 ### Workarounds Form Finishers can be adjusted in a way that they only execute an action if the submitted form contains some expected data. Alternatively a custom Finisher can be added as first finisher. ### References This regression was introduced with https://github.com/neos/form/commit/049d415295be8d4a0478ccba97dba1bb81649567 Original report: https://tickets.neos.io/#ticket/zoom/411 (internal)

CVE-2021-32697 Affected Neos/form Versions

3 component(s)
Fixed Versions:
4.3.35.0.95.1.3
Product / Package Ecosystem Affected Versions Fixed Version
neos/form
 Packagist
≥ 1.2.0
< 4.3.3
4.3.3
neos/form
 Packagist
≥ 5.0.0
< 5.0.9
5.0.9
neos/form
 Packagist
≥ 5.1.0
< 5.1.3
5.1.3

References

GitHub Advisory / Wiki ADVISORY
https://github.com/neos/form/security/advisories/GHSA-m5vx-8chx-qvmm
NVD — CVE-2021-32697 NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-32697
Neos/form Source Repository REPOSITORY
https://github.com/neos/form-ghsa-m5vx-8chx-qvmm/pull/1
Security Fix Commit FIX COMMIT
https://github.com/neos/form/commit/049d415295be8d4a0478ccba97dba1bb81649567
Security Fix Commit FIX COMMIT
https://github.com/neos/form/commit/69de4219b1f58157e2be6b05811463875d75c246
Neos/form Source Repository REPOSITORY
https://github.com/FriendsOfPHP/security-advisories/blob/master/neos/form/CVE-2021-32697.yaml
Neos/form Release RELEASE
https://github.com/neos/form/releases/tag/5.1.3

Frequently Asked Questions

What is CVE-2021-32697?
CVE-2021-32697 is a security vulnerability in Neos/form involving Form validation can be skipped under CWE-20: Improper Input Validation.
Which Neos/form versions are affected?
Affected versions include releases prior to 4.3.3, 5.0.9, 5.1.3 across affected packages: neos/form.
What version fixes CVE-2021-32697?
Upgrading to 4.3.3, 5.0.9, 5.1.3 (or the latest patched release for your respective branch) resolves the vulnerability.
Is neos/form affected?
Yes, neos/form is affected in releases prior to 4.3.3, 5.0.9, 5.1.3. Upgrade your dependency to 4.3.3, 5.0.9, 5.1.3 or later.
What is the CVSS score of CVE-2021-32697?
CVE-2021-32697 has a CVSS v3.1 base score of 6.5 (MODERATE) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N.
What CWE is associated with CVE-2021-32697?
CVE-2021-32697 is classified under CWE-20: Improper Input Validation (The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.).
How can I check Packagist dependencies for CVE-2021-32697?
Run the dependency tree command: 'inspect dependencies for neos/form'. 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-m5vx-8chx-qvmm",
  "modified" : "2021-07-29T14:34:11Z",
  "published" : "2021-06-22T15:15:08Z",
  "aliases" : [ "CVE-2021-32697" ],
  "summary" : "Form validation can be skipped",
  "details" : "### Impact\nBy crafting a special `GET` request containing a valid form state, a form can be submitted without invoking any validators.\nWe consider the severity _low_ because it is not possible to _change_ any form values since the form state is secured with an HMAC that is still verified.\nThat means that this issue can only be exploited if Form Finishers cause side effects even if no form values have been sent.\n\n### Patches\nhttps://github.com/neos/form/commit/69de4219b1f58157e2be6b05811463875d75c246\n\n### Workarounds\nForm Finishers can be adjusted in a way that they only execute an action if the submitted form contains some expected data.\nAlternatively a custom Finisher can be added as first finisher.\n\n### References\nThis regression was introduced with https://github.com/neos/form/commit/049d415295be8d4a0478ccba97dba1bb81649567\nOriginal report: https://tickets.neos.io/#ticket/zoom/411 (internal)",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "neos/form"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "1.2.0"
      }, {
        "fixed" : "4.3.3"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "neos/form"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "5.0.0"
      }, {
        "fixed" : "5.0.9"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "neos/form"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "5.1.0"
      }, {
        "fixed" : "5.1.3"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/neos/form/security/advisories/GHSA-m5vx-8chx-qvmm"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2021-32697"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/neos/form-ghsa-m5vx-8chx-qvmm/pull/1"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/neos/form/commit/049d415295be8d4a0478ccba97dba1bb81649567"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/neos/form/commit/69de4219b1f58157e2be6b05811463875d75c246"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/FriendsOfPHP/security-advisories/blob/master/neos/form/CVE-2021-32697.yaml"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/neos/form/releases/tag/5.1.3"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-20" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2021-06-21T17:39:52Z",
    "nvd_published_at" : "2021-06-21T19:15:00Z"
  }
}