CVE-2021-41228

Code injection in savedmodelcli

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Attribution

This vulnerability has been reported by Omer Kaspi from Vdoo.

TensorFlow's saved_model_cli tool is vulnerable to a code injection as it calls eval on user supplied strings

def preprocess_input_exprs_arg_string(input_exprs_str):
  ... 
  for input_raw in filter(bool, input_exprs_str.split(';')):
    ...
    input_key, expr = input_raw.split('=', 1)
    input_dict[input_key] = eval(expr)
  ...

This can be used by attackers to run arbitrary code on the plaform where the CLI tool runs.
However, given that the tool is always run manually, the impact of this is not severe. We have patched this by adding a safe flag which defaults to True and an explicit warning for users.

Untrusted input reaches a shell command, allowing arbitrary commands to run on the host. Typical impact: code execution in the application's environment.

CVE-2021-41228 has a CVSS score of 7.5 (Medium). The vector is requires local access, high 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 (2.5.2, 2.4.4, 2.6.1); upgrading removes the vulnerable code path.

Kodem intelligence

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We have patched the issue in GitHub commit 8b202f08d52e8206af2bdb2112a62fafbc546ec7.

The fix will be included in TensorFlow 2.7.0. We will also cherrypick this commit on TensorFlow 2.6.1, TensorFlow 2.5.2, and TensorFlow 2.4.4, as these are also affected and still in supported range.

1. What is CVE-2021-41228? CVE-2021-41228 is a medium-severity OS command injection vulnerability in tensorflow (pip), affecting versions >= 2.5.0, < 2.5.2. It is fixed in 2.5.2, 2.4.4, 2.6.1. Untrusted input reaches a shell command, allowing arbitrary commands to run on the host.
2. How severe is CVE-2021-41228? CVE-2021-41228 has a CVSS score of 7.5 (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-2021-41228?
   • tensorflow (pip) (versions >= 2.5.0, < 2.5.2)
   • tensorflow-cpu (pip) (versions >= 2.5.0, < 2.5.2)
   • tensorflow-gpu (pip) (versions >= 2.5.0, < 2.5.2)
4. Is there a fix for CVE-2021-41228? Yes. CVE-2021-41228 is fixed in 2.5.2, 2.4.4, 2.6.1. Upgrade to this version or later.
5. Is CVE-2021-41228 exploitable, and should I be worried? Whether CVE-2021-41228 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-2021-41228 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-2021-41228?
   • Upgrade tensorflow to 2.5.2 or later
   • Upgrade tensorflow to 2.4.4 or later
   • Upgrade tensorflow to 2.6.1 or later
   • Upgrade tensorflow-cpu to 2.5.2 or later
   • Upgrade tensorflow-cpu to 2.4.4 or later
   • Upgrade tensorflow-cpu to 2.6.1 or later
   • Upgrade tensorflow-gpu to 2.5.2 or later
   • Upgrade tensorflow-gpu to 2.4.4 or later
   • Upgrade tensorflow-gpu to 2.6.1 or later

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