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CVE Record

CVE-2021-29606: Heap OOB read in TFLite

TensorFlow is an end-to-end open source platform for machine learning. A specially crafted TFLite model could trigger an OOB read on heap in the TFLite implementation of `Split_V`(https://github.com/tensorflow/tensorflow/blob/c59c37e7b2d563967da813fa50fe20b21f4da683/tensorflow/lite/kernels/split_v.cc#L99). If `axis_value` is not a value between 0 and `NumDimensions(input)`, then the `SizeOfDimension` function(https://github.com/tensorflow/tensorflow/blob/102b211d892f3abc14f845a72047809b39cc65ab/tensorflow/lite/kernels/kernel_util.h#L148-L150) will access data outside the bounds of the tensor shape array. 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.

HighCVSS 7.1Not KEV-listedUpdated
Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

A maliciously crafted TensorFlow Lite model can make affected TensorFlow versions read beyond valid heap memory while processing Split_V. The published score is high because successful triggering can affect integrity and availability. The main business risk is in systems that accept or run TFLite models from users, partners, marketplaces, or automated pipelines.

Executive priority

Treat this as a high-priority dependency update for ML systems that run TFLite models. Urgency is highest where external model files are accepted. There is no provided evidence of active exploitation, so prioritization should be risk-based rather than emergency-driven.

Technical view

CVE-2021-29606 is a heap out-of-bounds read in TensorFlow Lite Split_V. If axis_value is outside 0 to NumDimensions(input), SizeOfDimension can access outside the tensor shape array. The advisory says the fix is in TensorFlow 2.5.0 and cherry-picked to supported 2.4.2, 2.3.3, 2.2.3, and 2.1.4 releases.

Likely exposure

Exposure is most likely where affected TensorFlow versions process TFLite models, especially if models can come from untrusted users, third parties, CI pipelines, or edge/mobile update channels.

Exploitation context

The source bundle does not show CISA KEV listing or cited evidence of active exploitation. The CVSS vector indicates local attack, low privileges, no user interaction, unchanged scope, no confidentiality impact, and high integrity and availability impact.

Researcher notes

The root condition is missing validation of axis_value before SizeOfDimension uses it against tensor shape metadata. Research should focus on affected TensorFlow Lite Split_V call paths and whether deployed products permit attacker-influenced model files. Do not assume products beyond TensorFlow without additional evidence.

Mitigation direction

  • Upgrade TensorFlow to 2.5.0 or a patched supported branch release.
  • Use 2.4.2, 2.3.3, 2.2.3, or 2.1.4 where those branches are required.
  • Restrict processing of untrusted TFLite models until patched.
  • Check downstream vendor guidance for embedded, packaged, or forked TensorFlow builds.
  • Prioritize systems that ingest models from users, partners, or automated supply chains.

Validation and detection

  • Inventory TensorFlow versions in applications, containers, SBOMs, and build manifests.
  • Identify services, mobile apps, and edge components that load TFLite models.
  • Confirm affected ranges are absent or replaced by patched releases.
  • Verify downstream builds include TensorFlow commit ae2daeb45abfe2c6dda539cf8d0d6f653d3ef412 or vendor-equivalent fixes.
  • Regression test model-loading paths after upgrade for compatibility and stability.
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-125: Exact CWE lookup

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cve · low confidence lookup

CVE-2021-29606 mapping review

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Vulnerability profileCVE Program record
Severity
High
CVSS
7.1 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:L/AC:L/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
7.1CVSS 3.1HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H1.85.2Primary CVE score

Vulnerability scoring details

Base CVSS 3.1 score

7.1High
CVSS 3.1 vector shape for CVE-2021-29606Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:L/AC:L/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-125 · source CWE mapping

Out-of-bounds Read

Out-of-bounds Read represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.