CVE-2013-4347 is a low-severity (CVSS 3.7) CWE-310 vulnerability in oauth2. A fix is available for oauth2 — see the affected versions and patch details below.
SimpleGeo python-oauth2 vulnerable to the use of Insufficiently Random Values to generate nonces
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
oauth2Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
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.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | oauth2 | all versions | 1.9rc1pip install --upgrade 'oauth2==1.9rc1' |
Affected Products
python-oauth2urbanairshipDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for oauth2, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update oauth2 to 1.9rc1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2013-4347 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
Frequently Asked Questions
Is CVE-2013-4347 in your dependencies?
Find it across PyPI, including transitive dependencies.