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CVE Record

CVE-2021-32697: Form validation can be skipped

neos/forms is an open source framework to build web forms. By crafting a special `GET` request containing a valid form state, a form can be submitted without invoking any validators. 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. 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. This regression was introduced with https://github.com/neos/form/commit/049d415295be8d4a0478ccba97dba1bb81649567

MediumCVSS 6.5Not KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

CVE-2021-32697 lets an attacker submit certain Neos Forms without normal validation, but only when they can use a valid signed form state. The main business risk is unintended side effects from form Finishers, such as workflows firing when expected form values were not actually submitted.

Executive priority

Treat as a moderate-priority web application issue. Patch during the next normal security maintenance window, sooner for public forms tied to lead capture, account workflows, payments, or operational automations.

Technical view

Affected neos/form versions can process a crafted GET request containing a valid HMAC-protected form state while skipping validators. The HMAC remains verified, so exposure depends on Finishers that perform actions even when submitted form data is missing. Affected ranges are >=1.2.0 <4.3.3, >=5.0.0 <5.0.9, and >=5.1.0 <5.1.3.

Likely exposure

Internet-facing Neos sites using affected neos/form versions are relevant, especially forms with Finishers that send messages, create records, trigger workflows, or otherwise act without checking expected submitted data.

Exploitation context

The CVSS vector indicates network, unauthenticated, low-complexity exploitation with no user interaction. The bundle does not show active exploitation or KEV listing. Practical impact is conditional because a valid form state is still required and the vulnerable Finisher behavior must produce side effects.

Researcher notes

The key constraint is that form state HMAC verification still succeeds; this is not described as signature bypass. Analysis should focus on validator bypass and Finisher side effects under empty or missing submitted values. The provided bundle does not include exploit-in-the-wild evidence.

Mitigation direction

  • Upgrade neos/form outside the listed affected ranges, such as 4.3.3, 5.0.9, or 5.1.3 and later.
  • Adjust Finishers to execute only when expected submitted form data is present.
  • Add a custom first Finisher to stop processing when required values are missing.
  • Prioritize review of forms whose Finishers create business or data side effects.
  • Check the GitHub advisory and release notes for deployment-specific guidance.

Validation and detection

  • Inventory deployed neos/form package versions against the affected ranges.
  • List all Neos Forms using Finishers with side effects.
  • Confirm Finishers check for expected submitted data before acting.
  • Review application logs for GET submissions with form state but absent form values.
  • Regression-test affected forms to confirm validation and Finisher gating both run.
Prepared
Confidence
high
Sources
5

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

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ATT&CK lookup starting points

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cwe · low confidence lookup

CWE-20: Exact CWE lookup

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cve · low confidence lookup

CVE-2021-32697 mapping review

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Vulnerability profileCVE Program record
Severity
Medium
CVSS
6.5 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

1CVSS vectors
0Timeline events
0ADP providers
6Source links

CVSS vector scores

1 official score

We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.

ScoreVersionSeverityVectorExploitImpactSource
6.5CVSS 3.1MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N3.92.5Primary CVE score

Vulnerability scoring details

Base CVSS 3.1 score

6.5Medium
CVSS 3.1 vector shape for CVE-2021-32697Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
HighLowNone

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
neosform>= 1.2.0, < 4.3.3, >= 5.0.0, < 5.0.9, >= 5.1.0, < 5.1.3Listed
Weakness

CWE details

CWE-20

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.