CVE-2021-3116

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).

CVSS v3 7.5 HIGH
CVSS v2.0 5.0 MEDIUM

7.5^/10

CVSS v3 : HIGH

Vector :

Exploitability : 3.9 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact HIGH

Availability Impact NONE

Scope UNCHANGED

5.0^/10

CVSS v2.0 : MEDIUM

Vector : AV:N/AC:L/Au:N/C:N/I:P/A:N

Exploitability : 10.0 / Impact : 2.9

Access Vector NETWORK

Access Complexity LOW

Authentication NONE

Confidentiality Impact NONE

Integrity Impact PARTIAL

Availability Impact NONE

References

Link	Resource
https://cardaci.xyz/advisories/2021/01/10/proxy.py-2.3.0-broken-basic-authentication/	Exploit Third Party Advisory
https://github.com/abhinavsingh/proxy.py/pull/482/commits/9b00093288237f5073c403f2c4f62acfdfa8ed46	Patch
https://pypi.org/project/proxy.py/2.3.1/#history	Product
https://cardaci.xyz/advisories/2021/01/10/proxy.py-2.3.0-broken-basic-authentication/	Exploit Third Party Advisory
https://github.com/abhinavsingh/proxy.py/pull/482/commits/9b00093288237f5073c403f2c4f62acfdfa8ed46	Patch
https://pypi.org/project/proxy.py/2.3.1/#history	Product

Configurations

Configuration 1 (hide)

cpe:2.3:a:proxy.py_project:proxy.py:*:*:*:*:*:*:*:*

History

No history.

Information

Published : 2021-01-11 05:15

Updated : 2026-06-17 04:04

NVD link : CVE-2021-3116

Mitre link : CVE-2021-3116

CVE.ORG link : CVE-2021-3116

JSON object : View

Products Affected

proxy.py_project

proxy.py

CWE

CWE-697

Incorrect Comparison

{"id": "CVE-2021-3116", "cveTags": [], "metrics": {"cvssMetricV2": [{"type": "Primary", "source": "nvd@nist.gov", "cvssData": {"version": "2.0", "baseScore": 5.0, "accessVector": "NETWORK", "vectorString": "AV:N/AC:L/Au:N/C:N/I:P/A:N", "authentication": "NONE", "integrityImpact": "PARTIAL", "accessComplexity": "LOW", "availabilityImpact": "NONE", "confidentialityImpact": "NONE"}, "acInsufInfo": false, "impactScore": 2.9, "baseSeverity": "MEDIUM", "obtainAllPrivilege": false, "exploitabilityScore": 10.0, "obtainUserPrivilege": false, "obtainOtherPrivilege": false, "userInteractionRequired": false}], "cvssMetricV31": [{"type": "Primary", "source": "nvd@nist.gov", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 7.5, "attackVector": "NETWORK", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "NONE", "privilegesRequired": "NONE", "confidentialityImpact": "NONE"}, "impactScore": 3.6, "exploitabilityScore": 3.9}]}, "affected": [{"source": "cve@mitre.org", "affectedData": [{"vendor": "n/a", "product": "n/a", "versions": [{"status": "affected", "version": "n/a"}]}]}], "published": "2021-01-11T05:15:10.987", "references": [{"url": "https://cardaci.xyz/advisories/2021/01/10/proxy.py-2.3.0-broken-basic-authentication/", "tags": ["Exploit", "Third Party Advisory"], "source": "cve@mitre.org"}, {"url": "https://github.com/abhinavsingh/proxy.py/pull/482/commits/9b00093288237f5073c403f2c4f62acfdfa8ed46", "tags": ["Patch"], "source": "cve@mitre.org"}, {"url": "https://pypi.org/project/proxy.py/2.3.1/#history", "tags": ["Product"], "source": "cve@mitre.org"}, {"url": "https://cardaci.xyz/advisories/2021/01/10/proxy.py-2.3.0-broken-basic-authentication/", "tags": ["Exploit", "Third Party Advisory"], "source": "af854a3a-2127-422b-91ae-364da2661108"}, {"url": "https://github.com/abhinavsingh/proxy.py/pull/482/commits/9b00093288237f5073c403f2c4f62acfdfa8ed46", "tags": ["Patch"], "source": "af854a3a-2127-422b-91ae-364da2661108"}, {"url": "https://pypi.org/project/proxy.py/2.3.1/#history", "tags": ["Product"], "source": "af854a3a-2127-422b-91ae-364da2661108"}], "vulnStatus": "Modified", "weaknesses": [{"type": "Primary", "source": "nvd@nist.gov", "description": [{"lang": "en", "value": "CWE-697"}]}], "descriptions": [{"lang": "en", "value": "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)."}, {"lang": "es", "value": "La funci\u00f3n before_upstream_connection en AuthPlugin en el archivo http/proxy/auth.py en proxy.py versiones anteriores a 2.3.1, acepta datos de encabezado Proxy-Authorization incorrectos debido a una confusi\u00f3n booleana (y versus o)"}], "lastModified": "2026-06-17T04:04:41.733", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:a:proxy.py_project:proxy.py:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "8B9F903B-99CF-482B-A91A-9117B1A7E890", "versionEndExcluding": "2.3.1"}], "operator": "OR"}]}], "sourceIdentifier": "cve@mitre.org"}