CVE-2020-4071 Timing attack on django-basic-auth-ip-whitelist
An attacker on the local network can potentially recover basic authentication credentials via timing analysis if basic auth is enabled.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2020-4071?
CVE-2020-4071 is a low-severity vulnerability in tm-kn django-basic-auth-ip-whitelist, published on 24 Jun 2020. It can only be exploited from the same machine or local network, with no action from the victim.
Official 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.
Weakness: CWE-208
Which versions are affected by CVE-2020-4071?
3 open source packages ship an affected version, including django-basic-auth-ip-whitelist. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
django-basic-auth-ip-whitelist PyPI | All versions | 0.3.4 |
django-basic-auth-ip-whitelist PyPI | All versions | 0.3.4 |
django-basic-auth-ip-whitelist PyPI | All versions | 0.3.4 |
Products include Django-Basic-Auth-Ip-Whitelist Project Django-Basic-Auth-Ip-Whitelist.
How do I fix CVE-2020-4071?
Upgrade django-basic-auth-ip-whitelist to 0.3.4 or later.
Is CVE-2020-4071 being exploited?
There is no known exploitation of CVE-2020-4071 in the wild and no public exploit code.
Sources
Also known as GHSA-m38j-pmg3-v5x5, PYSEC-2020-37.