CVE-2021-37666
📋 TL;DR
This vulnerability in TensorFlow allows an attacker to cause undefined behavior by triggering a null pointer dereference in the RaggedTensorToVariant operation. Attackers could potentially crash the application or execute arbitrary code. All systems running affected TensorFlow versions are vulnerable.
💻 Affected Systems
- TensorFlow
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete system compromise, data theft, or service disruption
Likely Case
Application crash causing denial of service and potential data corruption
If Mitigated
Limited impact with proper input validation and sandboxing in place
🎯 Exploit Status
Exploitation requires crafting specific input to trigger the null pointer dereference
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: TensorFlow 2.6.0, 2.5.1, 2.4.3, 2.3.4
Vendor Advisory: https://github.com/tensorflow/tensorflow/security/advisories/GHSA-w4xf-2pqw-5mq7
Restart Required: Yes
Instructions:
1. Update TensorFlow to patched version: pip install --upgrade tensorflow==2.6.0
2. Restart all TensorFlow services and applications
3. Verify the fix by checking version and testing RaggedTensorToVariant operations
🔧 Temporary Workarounds
Input validation wrapper
allAdd custom validation to check for empty splits before calling RaggedTensorToVariant
# Python code to wrap vulnerable function
import tensorflow as tf
def safe_ragged_tensor_to_variant(rt_nested_splits, rt_dense_values):
for splits in rt_nested_splits:
if splits.shape[0] == 0:
raise ValueError('Empty splits not allowed')
return tf.raw_ops.RaggedTensorToVariant(rt_nested_splits, rt_dense_values)
🧯 If You Can't Patch
- Disable or restrict access to RaggedTensorToVariant operations
- Implement strict input validation and sanitization for all TensorFlow inputs
🔍 How to Verify
Check if Vulnerable:
Check TensorFlow version: python -c 'import tensorflow as tf; print(tf.__version__)'Check Version:
python -c 'import tensorflow as tf; print(tf.__version__)'Verify Fix Applied:
Test RaggedTensorToVariant with empty splits input - should raise proper error instead of crashing📡 Detection & Monitoring
Log Indicators:
- Segmentation faults in TensorFlow processes
- Unexpected process termination
- Error logs mentioning RaggedTensorToVariant
Network Indicators:
- Unusual patterns of requests to TensorFlow serving endpoints
- Sudden service unavailability
SIEM Query:
process_name:tensorflow AND (event_type:crash OR exit_code:139)🔗 References
- https://github.com/tensorflow/tensorflow/commit/be7a4de6adfbd303ce08be4332554dff70362612
- https://github.com/tensorflow/tensorflow/security/advisories/GHSA-w4xf-2pqw-5mq7
- https://github.com/tensorflow/tensorflow/commit/be7a4de6adfbd303ce08be4332554dff70362612
- https://github.com/tensorflow/tensorflow/security/advisories/GHSA-w4xf-2pqw-5mq7
