CVE-2020-4071
LOWCVE-2020-4071 is a low-severity (CVSS 2.4) CWE-208 vulnerability in django-basic-auth-ip-whitelist. O3 Security confirms whether CVE-2020-4071 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Timing attack on django-basic-auth-ip-whitelist
Real-World Exposure
django-basic-auth-ip-whitelistReal-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
In django-basic-auth-ip-whitelist before 0.3.4, a potential timing attack exists on websites where the basic authentication is used or configured, i.e. BASIC_AUTH_LOGIN and BASIC_AUTH_PASSWORD is set. Currently the string comparison between configured credentials and the ones provided by users is performed through a character-by-character string comparison. This enables a possibility that attacker may time the time it takes the server to validate different usernames and password, and use this knowledge to work out the valid credentials. This attack is understood not to be realistic over the Internet. However, it may be achieved from within local networks where the website is hosted, e.g. from inside a data centre where a website's server is located. Sites protected by IP address whitelisting only are unaffected by this vulnerability. This vulnerability has been fixed on version 0.3.4 of django-basic-auth-ip-whitelist. Update to version 0.3.4 as soon as possible and change basic authentication username and password configured on a Django project using this package. A workaround without upgrading to version 0.3.4 is to stop using basic authentication and use the IP whitelisting component only. It can be achieved by not setting BASIC_AUTH_LOGIN and BASIC_AUTH_PASSWORD in Django project settings.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | django-basic-auth-ip-whitelist | all versions | 0.3.4 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for django-basic-auth-ip-whitelist. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update django-basic-auth-ip-whitelist to 0.3.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2020-4071 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.
How O3 protects you
O3 pinpoints whether CVE-2020-4071 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2020-4071. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2020-4071 in your dependencies?
O3 detects CVE-2020-4071 across PyPI dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.