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CVE Record

CVE-2021-29532: Heap out of bounds read in `RaggedCross`

TensorFlow is an end-to-end open source platform for machine learning. An attacker can force accesses outside the bounds of heap allocated arrays by passing in invalid tensor values to `tf.raw_ops.RaggedCross`. This is because the implementation(https://github.com/tensorflow/tensorflow/blob/efea03b38fb8d3b81762237dc85e579cc5fc6e87/tensorflow/core/kernels/ragged_cross_op.cc#L456-L487) lacks validation for the user supplied arguments. Each of the above branches call a helper function after accessing array elements via a `*_list[next_*]` pattern, followed by incrementing the `next_*` index. However, as there is no validation that the `next_*` values are in the valid range for the corresponding `*_list` arrays, this results in heap OOB reads. 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

CVE-2021-29532 is a low-severity TensorFlow memory safety issue. Invalid tensor values passed to RaggedCross can trigger heap out-of-bounds reads, likely causing limited disruption rather than data theft or system takeover based on the published CVSS impact.

Executive priority

Treat as routine patching unless affected TensorFlow workloads process untrusted ML inputs. Prioritize shared research, notebook, or model-serving environments where low-privileged users can influence tensor values.

Technical view

TensorFlow's RaggedCross implementation lacked validation before reading list elements indexed by next_* counters. Crafted invalid tensor values could make the kernel read outside heap-allocated arrays. The CVSS vector is local, high complexity, low privileges, no user interaction, unchanged scope, and low availability impact only.

Likely exposure

Exposure is mainly systems using affected TensorFlow versions with code paths that invoke tf.raw_ops.RaggedCross or equivalent RaggedCross behavior on untrusted or user-controlled tensor values.

Exploitation context

The bundle does not cite active exploitation, and KEV is false. Exploitation requires local access or equivalent ability to influence TensorFlow inputs, low privileges, and high attack complexity.

Researcher notes

The source evidence supports CWE-125 heap out-of-bounds read with availability-only CVSS impact. The advisory names affected version ranges and fixed releases, but the bundle does not provide evidence of exploitation in the wild.

Mitigation direction

  • Upgrade to TensorFlow 2.5.0 or a fixed supported backport release.
  • Use TensorFlow 2.4.2, 2.3.3, 2.2.3, or 2.1.4 where applicable.
  • Avoid processing untrusted tensor inputs through RaggedCross until patched.
  • Check vendor advisory and release guidance before applying workarounds.

Validation and detection

  • Inventory TensorFlow versions in applications, notebooks, containers, and ML serving images.
  • Search code for tf.raw_ops.RaggedCross and RaggedCross-dependent data pipelines.
  • Confirm dependency locks resolve to a fixed TensorFlow release.
  • Verify untrusted users cannot submit arbitrary tensors to affected pipelines.
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-125: Exact CWE lookup

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cve · low confidence lookup

CVE-2021-29532 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-2021-29532Attack 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-125 · source CWE mapping

Out-of-bounds Read

Out-of-bounds Read represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.