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CVE Record

CVE-2021-29601: Integer overflow in TFLite concatentation

TensorFlow is an end-to-end open source platform for machine learning. The TFLite implementation of concatenation is vulnerable to an integer overflow issue(https://github.com/tensorflow/tensorflow/blob/7b7352a724b690b11bfaae2cd54bc3907daf6285/tensorflow/lite/kernels/concatenation.cc#L70-L76). An attacker can craft a model such that the dimensions of one of the concatenation input overflow the values of `int`. TFLite uses `int` to represent tensor dimensions, whereas TF uses `int64`. Hence, valid TF models can trigger an integer overflow when converted to TFLite format. 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.

MediumCVSS 6.3Not KEV-listedUpdated
Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

This issue affects TensorFlow Lite's concatenation handling. A specially crafted ML model can cause an integer overflow when valid TensorFlow dimensions are represented as smaller TFLite integers. The main business risk is integrity and availability impact in systems that process untrusted models with affected TensorFlow versions.

Executive priority

Treat as a moderate-priority supply-chain and ML-platform maintenance issue. Prioritize environments that process third-party models or automate model conversion, because impact is integrity and availability rather than data confidentiality.

Technical view

TFLite uses int for tensor dimensions while TensorFlow uses int64. During concatenation, crafted model dimensions can overflow int, affecting TensorFlow versions before listed patched releases. CVSS 3.1 is 6.3 with local attack vector, high complexity, low privileges, no user interaction, and high integrity and availability impact.

Likely exposure

Exposure is most likely in ML pipelines, mobile or edge apps, or services that convert or execute TFLite models using affected TensorFlow releases and accept models from users, partners, plugins, or automated supply-chain inputs.

Exploitation context

The source bundle does not show active exploitation, and KEV is false. Exploitation requires a crafted model and local attack conditions with high complexity and low privileges, so risk rises where model ingestion is not tightly controlled.

Researcher notes

The key design mismatch is TensorFlow int64 dimensions versus TFLite int dimensions. The advisory states valid TensorFlow models can trigger overflow after TFLite conversion. Evidence in the bundle supports affected versions and planned fixed releases, but not in-the-wild exploitation.

Mitigation direction

  • Upgrade TensorFlow to 2.5.0 or the fixed supported branch release.
  • Use 2.4.2, 2.3.3, 2.2.3, or 2.1.4 where those branches are required.
  • Restrict ingestion and conversion of untrusted ML models.
  • Review vendor advisory and commit details for exact fixed behavior.
  • Inventory TensorFlow and TFLite use across build, training, and runtime environments.

Validation and detection

  • Check deployed TensorFlow versions against the affected ranges.
  • Identify workflows that convert TensorFlow models into TFLite format.
  • Confirm whether externally supplied models can reach TFLite concatenation processing.
  • Verify patched versions are present in application and build artifacts.
  • Document compensating controls for any systems awaiting upgrade.
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-190: Exact CWE lookup

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cve · low confidence lookup

CVE-2021-29601 mapping review

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Vulnerability profileCVE Program record
Severity
Medium
CVSS
6.3 (3.1)
Known Exploited
No
Published

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

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
6.3CVSS 3.1MediumCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:H15.2Primary CVE score

Vulnerability scoring details

Base CVSS 3.1 score

6.3Medium
CVSS 3.1 vector shape for CVE-2021-29601Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

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

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-190 · source CWE mapping

Integer Overflow or Wraparound

Integer Overflow or Wraparound represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.