CVE-2021-41201
📋 TL;DR
This CVE describes an uninitialized variable access vulnerability in TensorFlow's EinsumHelper::ParseEquation() function. The bug occurs when the function fails to properly set boolean flags to false, potentially leading to memory corruption or crashes. This affects TensorFlow users running affected versions who process einsum operations with ellipsis notation.
💻 Affected Systems
- TensorFlow
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Memory corruption leading to arbitrary code execution, denial of service, or information disclosure depending on how uninitialized memory is accessed.
Likely Case
Application crashes or instability when processing specific einsum operations with ellipsis notation.
If Mitigated
No impact if the vulnerable code path is not triggered or proper input validation prevents exploitation.
🎯 Exploit Status
Exploitation requires triggering the vulnerable code path with specific einsum operations. No public exploits are known at this time.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: TensorFlow 2.7.0, 2.6.1, 2.5.2, 2.4.4
Vendor Advisory: https://github.com/tensorflow/tensorflow/security/advisories/GHSA-j86v-p27c-73fm
Restart Required: Yes
Instructions:
1. Identify your TensorFlow version. 2. Upgrade to patched version: pip install tensorflow==2.7.0 (or appropriate version). 3. Restart any services using TensorFlow. 4. Test einsum operations to ensure stability.
🔧 Temporary Workarounds
Avoid einsum with ellipsis
allAvoid using einsum operations with ellipsis notation (three dots '...') in affected TensorFlow versions.
🧯 If You Can't Patch
- Implement input validation to reject or sanitize einsum operations containing ellipsis notation.
- Isolate TensorFlow services in containers with limited privileges to reduce potential impact.
🔍 How to Verify
Check if Vulnerable:
Check TensorFlow version: python -c 'import tensorflow as tf; print(tf.__version__)' and compare to affected versions.Check Version:
python -c 'import tensorflow as tf; print(tf.__version__)'Verify Fix Applied:
After patching, test einsum operations with ellipsis notation to ensure no crashes occur.📡 Detection & Monitoring
Log Indicators:
- Application crashes or segmentation faults when processing einsum operations
- Error messages related to memory access violations in TensorFlow logs
Network Indicators:
- Increased error rates in ML inference APIs using einsum operations
SIEM Query:
source="tensorflow" AND ("segmentation fault" OR "memory access" OR "einsum" OR "ellipsis")🔗 References
- https://github.com/tensorflow/tensorflow/commit/f09caa532b6e1ac8d2aa61b7832c78c5b79300c6
- https://github.com/tensorflow/tensorflow/security/advisories/GHSA-j86v-p27c-73fm
- https://github.com/tensorflow/tensorflow/commit/f09caa532b6e1ac8d2aa61b7832c78c5b79300c6
- https://github.com/tensorflow/tensorflow/security/advisories/GHSA-j86v-p27c-73fm
