CVE-2021-3116 Logic error in authentication in proxy.py
An attacker can bypass proxy authentication by sending incorrect Proxy-Authorization headers due to a boolean logic error in the proxy.py library.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2021-3116?
CVE-2021-3116 is a high-severity authentication bypass vulnerability in n/a, published on 11 Jan 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
before_upstream_connection in AuthPlugin in http/proxy/auth.py in proxy.py before 2.3.1 accepts incorrect Proxy-Authorization header data because of a boolean confusion (and versus or).
Weakness: CWE-697
Which versions are affected by CVE-2021-3116?
3 open source packages ship an affected version, including proxy-py and proxy.py. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
proxy-py PyPI | All versions | 2.3.1 |
proxy-py PyPI | All versions | 2.3.1 |
proxy.py PyPI | All versions | 2.3.1 |
Products include Proxy.py Project Proxy.py.
How do I fix CVE-2021-3116?
Upgrade proxy-py to 2.3.1 or later.
Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.
Is CVE-2021-3116 being exploited?
There is no known exploitation of CVE-2021-3116 in the wild and no public exploit code.
Sources
Also known as GHSA-cmc7-mfmr-xqrx, PYSEC-2021-46.