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Infinite loop in TFLite

Moderate severity GitHub Reviewed Published Aug 11, 2021 in tensorflow/tensorflow • Updated Feb 1, 2023

Package

pip tensorflow (pip)

Affected versions

< 2.3.4

Patched versions

2.3.4
pip tensorflow-cpu (pip)
>= 2.4.0, < 2.4.3
2.4.3
pip tensorflow-gpu (pip)
= 2.5.0
2.5.1

Description

Impact

The strided slice implementation in TFLite has a logic bug which can allow an attacker to trigger an infinite loop. This arises from newly introduced support for ellipsis in axis definition:

  for (int i = 0; i < effective_dims;) {
    if ((1 << i) & op_context->params->ellipsis_mask) {
      // ...
      int ellipsis_end_idx =
          std::min(i + 1 + num_add_axis + op_context->input_dims - begin_count,
                   effective_dims);
      // ...
      for (; i < ellipsis_end_idx; ++i) {
        // ...
      }
      continue;
    }
    // ...
    ++i;
  }

An attacker can craft a model such that ellipsis_end_idx is smaller than i (e.g., always negative). In this case, the inner loop does not increase i and the continue statement causes execution to skip over the preincrement at the end of the outer loop.

Patches

We have patched the issue in GitHub commit dfa22b348b70bb89d6d6ec0ff53973bacb4f4695.

The fix will be included in TensorFlow 2.6.0. This is the only affected version.

For more information

Please consult our security guide for more information regarding the security model and how to contact us with issues and questions.

Attribution

This vulnerability has been reported by members of the Aivul Team from Qihoo 360.

References

@mihaimaruseac mihaimaruseac published to tensorflow/tensorflow Aug 11, 2021
Published by the National Vulnerability Database Aug 12, 2021
Reviewed Aug 24, 2021
Published to the GitHub Advisory Database Aug 25, 2021
Last updated Feb 1, 2023

Severity

Moderate

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

EPSS score

0.042%
(5th percentile)

Weaknesses

CVE ID

CVE-2021-37686

GHSA ID

GHSA-mhhc-q96p-mfm9

Source code

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