CVE-2021-37692

Segfault on strings tensors with mistmatched dimensions, due to Go code

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Attribution

This vulnerability has been reported externally via a fixing PR.

Under certain conditions, Go code can trigger a segfault in string deallocation.

For string tensors, C.TF_TString_Dealloc is called during garbage collection within a finalizer function. However, tensor structure isn't checked until encoding to avoid a performance penalty. The current method for dealloc assumes that encoding succeeded, but segfaults when a string tensor is garbage collected whose encoding failed (e.g., due to mismatched dimensions).

To fix this, the call to set the finalizer function is deferred until NewTensor returns and, if encoding failed for a string tensor, deallocs are determined based on bytes written.

The application does not adequately validate input before processing it, allowing unexpected values to reach sensitive code paths. Typical impact: varies by context: data corruption, logic bypass, or denial of service.

CVE-2021-37692 has a CVSS score of 5.5 (Medium). The vector is requires local access, low privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (2.5.1); upgrading removes the vulnerable code path.

Kodem intelligence

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We have patched the issue in GitHub commit 8721ba96e5760c229217b594f6d2ba332beedf22 (merging #50508).

The fix will be included in TensorFlow 2.6.0. We will also cherrypick this commit on TensorFlow 2.5.1, which is the other affected version.

1. What is CVE-2021-37692? CVE-2021-37692 is a medium-severity improper input validation vulnerability in tensorflow (pip), affecting versions >= 2.5.0rc0, < 2.5.1. It is fixed in 2.5.1. The application does not adequately validate input before processing it, allowing unexpected values to reach sensitive code paths.
2. How severe is CVE-2021-37692? CVE-2021-37692 has a CVSS score of 5.5 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which packages are affected by CVE-2021-37692?
   • tensorflow (pip) (versions >= 2.5.0rc0, < 2.5.1)
   • tensorflow-cpu (pip) (versions >= 2.5.0rc0, < 2.5.1)
   • tensorflow-gpu (pip) (versions >= 2.5.0rc0, < 2.5.1)
4. Is there a fix for CVE-2021-37692? Yes. CVE-2021-37692 is fixed in 2.5.1. Upgrade to this version or later.
5. Is CVE-2021-37692 exploitable, and should I be worried? Whether CVE-2021-37692 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2021-37692 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2021-37692?
   • Upgrade tensorflow to 2.5.1 or later
   • Upgrade tensorflow-cpu to 2.5.1 or later
   • Upgrade tensorflow-gpu to 2.5.1 or later

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