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CVE Record

CVE-2021-29593: Division by zero in TFLite's implementation of `BatchToSpaceNd`

TensorFlow is an end-to-end open source platform for machine learning. The implementation of the `BatchToSpaceNd` TFLite operator is vulnerable to a division by zero error(https://github.com/tensorflow/tensorflow/blob/b5ed552fe55895aee8bd8b191f744a069957d18d/tensorflow/lite/kernels/batch_to_space_nd.cc#L81-L82). An attacker can craft a model such that one dimension of the `block` input is 0. Hence, the corresponding value in `block_shape` is 0. The fix will be included in TensorFlow 2.5.0. We will also cherrypick this commit on TensorFlow 2.4.2, TensorFlow 2.3.3, TensorFlow 2.2.3 and TensorFlow 2.1.4, as these are also affected and still in supported range.

LowCVSS 2.5Not KEV-listedUpdated
Glexia's TakeAutomated analysislow

Security readout for executives and security teams

Plain-English summary

This is a low-severity TensorFlow Lite denial-of-service issue. A crafted model can cause a divide-by-zero crash in the BatchToSpaceNd operator. Business urgency is highest where untrusted or customer-supplied models are loaded by affected TensorFlow versions.

Executive priority

Treat as routine patching unless the organization processes untrusted models. For exposed model-ingestion workflows, schedule remediation promptly because the impact is service disruption, not data compromise.

Technical view

TensorFlow Lite BatchToSpaceNd can divide by zero when a crafted model sets a block input dimension to 0, making block_shape 0. CVSS 3.1 is 2.5: local attack vector, high complexity, low privileges, and low availability impact only.

Likely exposure

Exposure is likely limited to applications using affected TensorFlow or TFLite versions that load crafted or untrusted models. Systems using only trusted models or patched releases have materially lower exposure.

Exploitation context

The source bundle does not indicate active exploitation, KEV listing, public exploitation, or remote attackability. The advisory describes a crafted model causing a local availability impact.

Researcher notes

This is CWE-369 in TFLite BatchToSpaceNd. The cited advisory ties the issue to zero-valued block_shape input and patched TensorFlow releases. Evidence supports availability impact only; confidentiality and integrity impact are not indicated.

Mitigation direction

  • Upgrade to TensorFlow 2.5.0 or patched supported maintenance releases.
  • For 2.4, 2.3, 2.2, and 2.1 branches, use the vendor cherry-picked fixes.
  • Do not load untrusted TFLite models until patched or appropriately sandboxed.
  • Check TensorFlow advisory guidance for version-specific remediation.

Validation and detection

  • Inventory TensorFlow and TensorFlow Lite versions in applications and build artifacts.
  • Identify services or edge apps that load externally supplied TFLite models.
  • Confirm affected versions are no longer present in dependency manifests or runtime images.
  • Review model provenance controls for untrusted or customer-provided models.
Prepared
Confidence
high
Sources
4

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-369: Exact CWE lookup

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cve · low confidence lookup

CVE-2021-29593 mapping review

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Vulnerability profileCVE Program record
Severity
Low
CVSS
2.5 (3.1)
Known Exploited
No
Published

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

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
3Source 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
2.5CVSS 3.1LowCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L11.4Primary CVE score

Vulnerability scoring details

Base CVSS 3.1 score

2.5Low
CVSS 3.1 vector shape for CVE-2021-29593Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

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

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

Products and packages named in the record

VendorProductVersion / packageStatus
tensorflowtensorflow< 2.1.4, >= 2.2.0, < 2.2.3, >= 2.3.0, < 2.3.3, >= 2.4.0, < 2.4.2Listed
Weakness

CWE details

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

CWE-369 · source CWE mapping

Divide By Zero

Divide By Zero represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.