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CVE Record

CVE-2021-37653: Division by 0 in `ResourceGather` in TensorFlow

TensorFlow is an end-to-end open source platform for machine learning. In affected versions an attacker can trigger a crash via a floating point exception in `tf.raw_ops.ResourceGather`. The [implementation](https://github.com/tensorflow/tensorflow/blob/f24faa153ad31a4b51578f8181d3aaab77a1ddeb/tensorflow/core/kernels/resource_variable_ops.cc#L725-L731) computes the value of a value, `batch_size`, and then divides by it without checking that this value is not 0. We have patched the issue in GitHub commit ac117ee8a8ea57b73d34665cdf00ef3303bc0b11. 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

CVE-2021-37653 is a TensorFlow denial-of-service issue. A user who can run affected TensorFlow operations can crash the process by triggering a divide-by-zero condition in ResourceGather. The documented impact is availability loss, not data theft or code execution.

Executive priority

Treat this as a medium-priority availability risk. Escalate where TensorFlow runs in shared platforms or production ML services, because a crash can interrupt workloads. It is less urgent than code execution or data exposure issues.

Technical view

Affected TensorFlow versions divide by a computed batch_size in tf.raw_ops.ResourceGather without first checking for zero. This can cause a floating point exception and process crash. The issue is CWE-369 and has CVSS 3.1 score 5.5 with local, low-complexity, low-privilege attack conditions.

Likely exposure

Exposure is most likely in systems running vulnerable TensorFlow versions where local users, notebooks, jobs, or application inputs can invoke TensorFlow graph operations. The source bundle identifies TensorFlow only; no other affected products are evidenced.

Exploitation context

The CVE is not listed as KEV, and the provided sources do not show active exploitation. The attack model is local with low privileges and no user interaction, so shared ML environments deserve more attention than isolated developer machines.

Researcher notes

The fix is commit ac117ee8a8ea57b73d34665cdf00ef3303bc0b11, which addresses unchecked zero division in ResourceGather. The provided evidence supports denial of service only. No public exploitation evidence is included in the bundle.

Mitigation direction

  • Upgrade TensorFlow to a fixed release for the deployed branch.
  • Use TensorFlow 2.6.0 or later where feasible.
  • For maintained older branches, use 2.5.1, 2.4.3, or 2.3.4 as applicable.
  • Review vendor guidance before relying on compensating controls.
  • Limit untrusted users' ability to run arbitrary TensorFlow operations until patched.

Validation and detection

  • Inventory TensorFlow versions in applications, notebooks, containers, and ML jobs.
  • Compare installed versions against the affected ranges in the advisory.
  • Prioritize shared or user-driven ML execution environments.
  • Confirm patched versions are deployed after remediation.
  • Check dependency lockfiles and container images for stale TensorFlow packages.
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-2021-37653 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-2021-37653Attack 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.