CVE-2021-3116 json
Logic error in authentication in proxy.py
published 2021-01-11 5 y ago modified 2026-06-17 4 mo ago also GHSA-cmc7-mfmr-xqrx , PYSEC-2021-46 , EUVD-2021-0203
- cvss
- 7.5
- version 3.1, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 1.7%
- EPSS 1.7% chance of exploitation in 30 days, percentile 77%
- public exploits
- 0
- none known
Summary
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).
Patch / fix
- pypi proxy-py 2.3.1
- proxy.py_project proxy.py 2.3.1
- github.com/abhinavsingh/proxy.py#482 commit
- github.com/abhinavsingh/proxy.py@bff171e commit
- github.com/abhinavsingh/proxy.py#482 pull request
Exploit prediction
1.69% chance of exploitation in the next 30 days, higher than 77% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- cardaci.xyz https://cardaci.xyz/advisories/2021/01/10/proxy.py-2.3.0-broken-basic-authentication/ referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| NVD | 3.1 | 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N |
| NVD | 2.0 | 5.0 | AV:N/AC:L/Au:N/C:N/I:P/A:N |
| GitHub | 3.1 | 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| pypi | proxy-py | <2.3.1 |
2.3.1 |
Classification
References
-
github.com
/abhinavsingh/proxy.py/pull/482/commits/9b00093288237f5073c403f2c4f62acfdfa8ed46
web, patch
-
github.com
/abhinavsingh/proxy.py/pull/482
web
-
github.com
/abhinavsingh/proxy.py/commit/bff171ec26d826ae1d22d2466eaf9d8bdbf059d3
web
-
cardaci.xyz
/advisories/2021/01/10/proxy.py-2.3.0-broken-basic-authentication/
exploit, third-party-advisory, advisory
-
pypi.org
/project/proxy.py/2.3.1/#history
web, product, package
-
nvd.nist.gov
/vuln/detail/CVE-2021-3116
advisory
-
cardaci.xyz
/advisories/2021/01/10/proxy.py-2.3.0-broken-basic-authentication
web
-
github.com
/abhinavsingh/proxy.py
package
-
github.com
/advisories/GHSA-cmc7-mfmr-xqrx
advisory
-
github.com
/pypa/advisory-database/tree/main/vulns/proxy-py/PYSEC-2021-46.yaml
web
Sources
- CVE List CVE-2021-3116
- GitHub Advisory GHSA-cmc7-mfmr-xqrx
- NVD CVE-2021-3116
- OSV PYSEC-2021-46
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.