CVE-2022-21726

8.1 HIGH

📋 TL;DR

This vulnerability in TensorFlow's Dequantize operation allows attackers to read past the end of memory arrays by providing invalid axis values, potentially exposing sensitive data or causing crashes. It affects all TensorFlow users who process quantized tensors with the vulnerable operation. The issue stems from insufficient validation of the axis parameter.

💻 Affected Systems

Products:
  • TensorFlow
Versions: TensorFlow 2.5.0 through 2.7.0, and potentially earlier versions using the vulnerable code.
Operating Systems: All platforms running TensorFlow
Default Config Vulnerable: ⚠️ Yes
Notes: Only affects systems using the Dequantize operation with quantized tensors. The vulnerability is present in the default configuration when this operation is invoked.

📦 What is this software?

⚠️ Risk & Real-World Impact

🔴

Worst Case

Memory corruption leading to arbitrary code execution, data exfiltration, or complete system compromise through heap-based out-of-bounds reads.

🟠

Likely Case

Application crashes, denial of service, or information disclosure through memory leakage of adjacent data structures.

🟢

If Mitigated

Limited impact with proper input validation and sandboxing, potentially just crashes in isolated environments.

🌐 Internet-Facing: MEDIUM - Requires specific TensorFlow operations to be exposed via APIs, but common in ML inference services.
🏢 Internal Only: MEDIUM - Data processing pipelines and internal ML systems could be affected if processing untrusted inputs.

🎯 Exploit Status

Public PoC: ✅ No
Weaponized: UNKNOWN
Unauthenticated Exploit: ✅ No
Complexity: MEDIUM

Exploitation requires control over the axis parameter in Dequantize operations. While no public exploits exist, the vulnerability is well-documented in the advisory.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: TensorFlow 2.8.0, 2.7.1, 2.6.3, and 2.5.3

Vendor Advisory: https://github.com/tensorflow/tensorflow/security/advisories/GHSA-23hm-7w47-xw72

Restart Required: No

Instructions:

1. Identify your TensorFlow version. 2. Upgrade to patched version: pip install --upgrade tensorflow==2.8.0 (or appropriate version). 3. Verify the update with import tensorflow; print(tensorflow.__version__).

🔧 Temporary Workarounds

Input Validation Wrapper

all

Implement custom validation for axis parameter before calling Dequantize operations

# Python example:
def safe_dequantize(tensor, axis=-1):
    if axis >= tensor.shape.rank:
        raise ValueError('Axis out of bounds')
    return tf.raw_ops.Dequantize(input=tensor, axis=axis)

🧯 If You Can't Patch

  • Disable or restrict access to services using TensorFlow Dequantize operations
  • Implement strict input validation and sanitization for all tensor processing pipelines

🔍 How to Verify

Check if Vulnerable:

Check TensorFlow version: python -c 'import tensorflow as tf; print(tf.__version__)' and compare to affected versions (2.5.0-2.7.0).

Check Version:

python -c 'import tensorflow as tf; print(tf.__version__)'

Verify Fix Applied:

After patching, verify version is 2.8.0, 2.7.1, 2.6.3, or 2.5.3. Test Dequantize with edge cases to ensure proper bounds checking.

📡 Detection & Monitoring

Log Indicators:

  • TensorFlow segmentation faults
  • Memory access violation errors
  • Unexpected application crashes during tensor operations

Network Indicators:

  • Unusual patterns in ML inference API calls with axis parameters

SIEM Query:

process.name:"python" AND (event.action:"segmentation_fault" OR log.message:"tensorflow.*Dequantize")

🔗 References

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