CVE-2021-29581

Segfault in `CTCBeamSearchDecoder`

MEDIUM

5.5

CVSS Score

Published: May 14, 2021 at 07:15 PM UTC

Updated: June 17, 2026 at 03:47 AM UTC

2 products affected across 2 vendorsTensorflowTensorFlow

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Severity

MEDIUM5.5

Exploit prediction

EPSS 0.2%

Description

TensorFlow is an end-to-end open source platform for machine learning. Due to lack of validation in `tf.raw_ops.CTCBeamSearchDecoder`, an attacker can trigger denial of service via segmentation faults. The implementation(https://github.com/tensorflow/tensorflow/blob/a74768f8e4efbda4def9f16ee7e13cf3922ac5f7/tensorflow/core/kernels/ctc_decoder_ops.cc#L68-L79) fails to detect cases when the input tensor is empty and proceeds to read data from a null buffer. 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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Tensorflow · Google

95%

v < 2.1.42.2.0 ≤ v < 2.2.32.3.0 ≤ v < 2.3.32.4.0 ≤ v < 2.4.2

Affected range stops below 2.1.4, so it looks safe — our inference, not a vendor statement

Affected range stops below 2.2.3, so it looks safe — our inference, not a vendor statement

Affected range stops below 2.3.3, so it looks safe — our inference, not a vendor statement

Affected range stops below 2.4.2, so it looks safe — our inference, not a vendor statement

TensorFlow · Tensorflow

60%

v < 2.1.4v < 2.2.3v < 2.3.3v < 2.4.2

Affected range stops below 2.1.4, so it looks safe — our inference, not a vendor statement

Affected range stops below 2.2.3, so it looks safe — our inference, not a vendor statement

Affected range stops below 2.3.3, so it looks safe — our inference, not a vendor statement

Affected range stops below 2.4.2, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

Patch and advisory references

References (2)

x_refsource_MISCPatchThird Party Advisory

Source: [email protected]

https://github.com/tensorflow/tensorflow/commit/b1b323042264740c398140da32e93fb9c2c9f33e

x_refsource_CONFIRMExploitPatchThird Party Advisory

Source: [email protected]

https://github.com/tensorflow/tensorflow/security/advisories/GHSA-vq2r-5xvm-3hc3

CVSS

5.5MEDIUM[email protected]

Attack Vector: LOCAL
Complexity: LOW
Privileges: LOW
User Interaction: NONE
Scope: UNCHANGED
Confidentiality: NONE
Integrity: NONE
Availability: HIGH

Vector?

Quick Info

StatusMODIFIED

CWE

CWE-908

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