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CVE Record

CVE-2021-29513: Type confusion during tensor casts lead to dereferencing null pointers

TensorFlow is an end-to-end open source platform for machine learning. Calling TF operations with tensors of non-numeric types when the operations expect numeric tensors result in null pointer dereferences. The conversion from Python array to C++ array(https://github.com/tensorflow/tensorflow/blob/ff70c47a396ef1e3cb73c90513da4f5cb71bebba/tensorflow/python/lib/core/ndarray_tensor.cc#L113-L169) is vulnerable to a type confusion. 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

A TensorFlow flaw can make certain operations crash when given non-numeric tensors where numeric tensors are expected. The business impact is limited availability disruption in local or already-authorized contexts, not data theft or remote compromise based on the provided sources. Organizations using affected TensorFlow versions should prioritize routine dependency updates.

Executive priority

Handle through normal patch governance unless TensorFlow is exposed in multi-user ML platforms or customer-submitted workload processing. The issue is low severity and availability-only, but outdated ML dependencies can accumulate operational risk.

Technical view

TensorFlow's Python-to-C++ array conversion had type confusion. Operations expecting numeric tensors could receive non-numeric tensors and dereference null pointers. CVSS is 2.5 with local access, high complexity, low availability impact, and no confidentiality or integrity impact. Affected ranges include TensorFlow before 2.1.4 and specific 2.2.x, 2.3.x, and 2.4.x releases.

Likely exposure

Exposure is likely limited to applications or workflows running affected TensorFlow versions where local or authenticated users, jobs, or trusted code paths can submit tensors to vulnerable operations. The source bundle does not indicate default network-reachable exposure.

Exploitation context

The bundle reports no CISA KEV listing and provides no cited evidence of active exploitation. CVSS indicates local access, high complexity, and low availability impact only. Treat this as a stability or denial-of-service risk, especially in shared ML environments.

Researcher notes

The public bundle identifies CWE-476 and a type confusion path in ndarray_tensor.cc during Python array to C++ array conversion. Evidence is sufficient for affected-version tracking, but it does not include proof of active exploitation or broader product impact.

Mitigation direction

  • Upgrade to TensorFlow 2.5.0 or a fixed supported branch release named by the advisory.
  • Use TensorFlow 2.4.2, 2.3.3, 2.2.3, or 2.1.4 where those branches are required.
  • Review vendor advisory and commit details before accepting residual risk.
  • Restrict who can run untrusted TensorFlow workloads in shared environments.

Validation and detection

  • Inventory TensorFlow versions in applications, notebooks, containers, and training images.
  • Confirm no deployed package matches the affected version ranges.
  • Check dependency lockfiles and image manifests for transitive TensorFlow installs.
  • Run existing unit and workload tests after upgrading TensorFlow.
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-476: Exact CWE lookup

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cve · low confidence lookup

CVE-2021-29513 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-2021-29513Attack 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-476 · source CWE mapping

NULL Pointer Dereference

NULL Pointer Dereference represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.