CVE-2021-29518

Session operations in eager mode lead to null pointer dereferences

HIGH

7.8

CVSS Score

Published: May 14, 2021 at 07:36 PM UTC

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

2 products affected across 2 vendorsTensorflowTensorFlow

Using tensorflow by tensorflow?

Get instant alerts when new vulnerabilities affect tensorflow - before attackers find them.

Real-time alertsTrack your software stackFree plan available

Start Free Sign In

Severity

HIGH7.8

Exploit prediction

EPSS 0.2%

Description

TensorFlow is an end-to-end open source platform for machine learning. In eager mode (default in TF 2.0 and later), session operations are invalid. However, users could still call the raw ops associated with them and trigger a null pointer dereference. The implementation(https://github.com/tensorflow/tensorflow/blob/eebb96c2830d48597d055d247c0e9aebaea94cd5/tensorflow/core/kernels/session_ops.cc#L104) dereferences the session state pointer without checking if it is valid. Thus, in eager mode, `ctx->session_state()` is nullptr and the call of the member function is undefined behavior. 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/ff70c47a396ef1e3cb73c90513da4f5cb71bebba

x_refsource_CONFIRMExploitPatchThird Party Advisory

Source: [email protected]

https://github.com/tensorflow/tensorflow/security/advisories/GHSA-62gx-355r-9fhg

CVSS

7.8HIGH[email protected]

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

Vector?

Quick Info

StatusMODIFIED

CWE

CWE-476

Get alerted

Stop reading CVE feeds looking for your own stack

Track the products you run and VulnTracker tells you when a new CVE affects them — with what is known about fixing it, and nothing about the rest.

Create account Sign in

Free plan, no card