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CVE Record

CVE-2021-37636: Floating point exception in `SparseDenseCwiseDiv` in TensorFlow

TensorFlow is an end-to-end open source platform for machine learning. In affected versions the implementation of `tf.raw_ops.SparseDenseCwiseDiv` is vulnerable to a division by 0 error. The [implementation](https://github.com/tensorflow/tensorflow/blob/a1bc56203f21a5a4995311825ffaba7a670d7747/tensorflow/core/kernels/sparse_dense_binary_op_shared.cc#L56) uses a common class for all binary operations but fails to treat the division by 0 case separately. We have patched the issue in GitHub commit d9204be9f49520cdaaeb2541d1dc5187b23f31d9. The fix will be included in TensorFlow 2.6.0. We will also cherrypick this commit on TensorFlow 2.5.1, TensorFlow 2.4.3, and TensorFlow 2.3.4, as these are also affected and still in supported range.

MediumCVSS 5.5Not KEV-listedUpdated
Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

Affected TensorFlow versions can crash when a specific sparse/dense division operation hits a zero-division case. This is an availability issue, not a data theft issue. Business urgency is moderate and depends on whether untrusted users or jobs can run TensorFlow workloads in your environment.

Executive priority

Treat as a moderate availability risk. Prioritize patching shared ML platforms, hosted notebooks, and any service where untrusted users can run TensorFlow workloads. Lower priority is reasonable for isolated, trusted-only research environments.

Technical view

CVE-2021-37636 is a CWE-369 divide-by-zero flaw in tf.raw_ops.SparseDenseCwiseDiv. TensorFlow reused shared binary-operation logic without special handling for division by zero, causing a floating point exception. CVSS 3.1 is 5.5: local attack vector, low complexity, low privileges, no user interaction, high availability impact.

Likely exposure

Exposure is limited to TensorFlow installations in the affected version ranges: before 2.3.4, 2.4.0 through before 2.4.3, and 2.5.0 through before 2.5.1. Risk is higher where users can submit or execute TensorFlow models, notebooks, or jobs.

Exploitation context

The source bundle does not show active exploitation, and KEV is false. The described impact is denial of service through a local, low-privileged ability to run the affected TensorFlow operation. No confidentiality or integrity impact is identified in the supplied CVSS vector.

Researcher notes

The public details identify a divide-by-zero condition in SparseDenseCwiseDiv and cite TensorFlow commit d9204be9f49520cdaaeb2541d1dc5187b23f31d9 as the patch. Evidence supports crash/availability impact only. The bundle does not provide evidence of remote exploitation or broader product impact.

Mitigation direction

  • Upgrade TensorFlow to 2.6.0 or later where practical.
  • Use TensorFlow 2.5.1, 2.4.3, or 2.3.4 for supported older branches.
  • Identify containers, notebooks, and services bundling affected TensorFlow versions.
  • Restrict untrusted TensorFlow workload execution until upgraded.
  • Monitor TensorFlow advisory channels for any additional guidance.

Validation and detection

  • Check runtime and dependency lockfiles for affected TensorFlow versions.
  • Confirm deployed container images include a patched TensorFlow build.
  • Review ML job platforms for tenant-supplied TensorFlow execution paths.
  • Search codebases for use of tf.raw_ops.SparseDenseCwiseDiv.
  • Run normal regression 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

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

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-2021-37636 mapping review

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Vulnerability profileCVE Program record
Severity
Medium
CVSS
5.5 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/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
5.5CVSS 3.1MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H1.83.6Primary CVE score

Vulnerability scoring details

Base CVSS 3.1 score

5.5Medium
CVSS 3.1 vector shape for CVE-2021-37636Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/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>= 2.5.0, < 2.5.1, >= 2.4.0, < 2.4.3, < 2.3.4Listed
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.