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CVE Record

CVE-2021-29539: Segfault in tf.raw_ops.ImmutableConst

TensorFlow is an end-to-end open source platform for machine learning. Calling `tf.raw_ops.ImmutableConst`(https://www.tensorflow.org/api_docs/python/tf/raw_ops/ImmutableConst) with a `dtype` of `tf.resource` or `tf.variant` results in a segfault in the implementation as code assumes that the tensor contents are pure scalars. We have patched the issue in 4f663d4b8f0bec1b48da6fa091a7d29609980fa4 and will release TensorFlow 2.5.0 containing the patch. TensorFlow nightly packages after this commit will also have the issue resolved. If using `tf.raw_ops.ImmutableConst` in code, you can prevent the segfault by inserting a filter for the `dtype` argument.

LowCVSS 2.5Not KEV-listedUpdated
Glexia's TakeAutomated analysislow

Security readout for executives and security teams

Plain-English summary

This TensorFlow flaw can crash a process when a specific low-level operation is called with unsupported data types. It does not expose data or alter results, but it can cause limited downtime where TensorFlow executes untrusted or user-controlled model code.

Executive priority

Treat this as a low-priority availability risk unless TensorFlow is exposed to untrusted model execution. Patch during normal maintenance, but prioritize sooner for shared ML platforms where one user can crash worker processes affecting others.

Technical view

CVE-2021-29539 is a segfault in tf.raw_ops.ImmutableConst when dtype is tf.resource or tf.variant. The implementation assumed tensor contents were scalar, causing a crash. The issue is local, high-complexity, low-privilege, and availability-only per CVSS 3.1 score 2.5.

Likely exposure

Exposure is most relevant in ML platforms, notebooks, model-serving systems, or pipelines that allow low-privileged users to run TensorFlow operations or submit model graphs. Standard applications that do not expose TensorFlow execution to untrusted input are less likely to be affected.

Exploitation context

The provided sources do not report active exploitation, and the CVE is not listed as KEV. Exploitation requires local or equivalent ability to execute TensorFlow code that reaches ImmutableConst with the problematic dtype, so business impact is mainly process crash or job interruption.

Researcher notes

The root issue is a type assumption in ImmutableConst. Sources identify CWE-681 and affected TensorFlow maintenance ranges. No source confirms remote exploitation or broader product impact. Validation should focus on reachable low-level op usage and execution boundaries for untrusted TensorFlow workloads.

Mitigation direction

  • Upgrade TensorFlow to a patched release outside the affected version ranges, such as 2.5.0 or later.
  • Use TensorFlow nightly builds only if they include commit 4f663d4b8f0bec1b48da6fa091a7d29609980fa4 or later.
  • If using tf.raw_ops.ImmutableConst, filter dtype to block tf.resource and tf.variant.
  • Check vendor guidance before relying on compensating controls instead of upgrading.

Validation and detection

  • Inventory deployed TensorFlow versions against the affected version ranges in the advisory.
  • Review code and model pipelines for direct use of tf.raw_ops.ImmutableConst.
  • Confirm any ImmutableConst usage rejects tf.resource and tf.variant dtype values.
  • Assess whether untrusted users can submit TensorFlow code, graphs, or models for execution.
  • Track remediation evidence to the TensorFlow advisory and patch commit.
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-681: Exact CWE lookup

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cve · low confidence lookup

CVE-2021-29539 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-2021-29539Attack 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-681 · source CWE mapping

Incorrect Conversion between Numeric Types

Incorrect Conversion between Numeric Types represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.