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CVE Record

CVE-2021-29524: Division by 0 in `Conv2DBackpropFilter`

TensorFlow is an end-to-end open source platform for machine learning. An attacker can trigger a division by 0 in `tf.raw_ops.Conv2DBackpropFilter`. This is because the implementation(https://github.com/tensorflow/tensorflow/blob/496c2630e51c1a478f095b084329acedb253db6b/tensorflow/core/kernels/conv_grad_shape_utils.cc#L130) does a modulus operation where the divisor is controlled by the caller. 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

This is a low-severity TensorFlow denial-of-service flaw. A user who can run affected TensorFlow code can trigger a divide-by-zero crash path in a convolution backpropagation operation. The main business risk is disruption of ML jobs or services, not data theft or privilege escalation.

Executive priority

Handle through normal patch management unless TensorFlow workloads are exposed to untrusted internal users or shared ML platforms. The issue is availability-focused and low severity, but stale ML dependencies should still be cleared from production and shared research environments.

Technical view

CVE-2021-29524 affects TensorFlow Conv2DBackpropFilter through a caller-controlled divisor used in a modulus operation. CVSS is 2.5, local, high complexity, low privileges, no confidentiality or integrity impact, and low availability impact. Fixed releases were planned for 2.5.0 and supported backports.

Likely exposure

Exposure is most plausible in environments running affected TensorFlow versions where users can execute TensorFlow ops, submit ML jobs, or influence graph parameters. The source does not identify affected hosted services, downstream products, or remote unauthenticated exposure.

Exploitation context

The source states an attacker can trigger the issue, but CISA KEV status is false and no provided source reports active exploitation. The CVSS vector indicates local access, low privileges, high attack complexity, and availability-only impact.

Researcher notes

The evidence identifies CWE-369 and a vulnerable modulus operation in TensorFlow conv_grad_shape_utils.cc. The bundle provides affected version ranges and the fixing commit, but no exploit telemetry, proof-of-concept details, or downstream product mapping.

Mitigation direction

  • Upgrade TensorFlow to 2.5.0 or the fixed supported backport for your branch.
  • Use TensorFlow 2.4.2, 2.3.3, 2.2.3, or 2.1.4 where applicable.
  • Check TensorFlow advisory guidance before choosing a legacy branch fix.
  • Reduce untrusted access to TensorFlow job execution environments.

Validation and detection

  • Inventory TensorFlow versions in application images, notebooks, training workers, and ML pipelines.
  • Flag versions below 2.1.4, 2.2.3, 2.3.3, or 2.4.2 as affected.
  • Confirm upgraded environments load the intended patched TensorFlow version.
  • Review logs for unexplained TensorFlow job crashes in shared compute environments.
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-2021-29524 mapping review

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Open ATT&CK lookup
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-2021-29524Attack 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-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.