CVE-2021-28363
What it is
The urllib3 library 1.26.x before 1.26.4 for Python omits SSL certificate validation in some cases involving HTTPS to HTTPS proxies. The initial connection to the HTTPS proxy (if an SSLContext isn't given via proxy_config) doesn't verify the hostname of the certificate. This means certificates for different servers that still validate properly with the default urllib3 SSLContext will be silently accepted.
At a glance
- Exploitability
- Can be exploited over the network without logging in. Limited direct impact.
- Exploit odds
- 2.2% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 2.2% in the next 30 days (EPSS).
- Severity: 6.5 MEDIUM (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 2.2% · EPSS, next 30 days
- Weakness
- CWE-295 · Improper certificate validation
- Record status
- Modified
Affected
- Python urllib3 < 1.26.4
- Fedoraproject Fedora 34
- Oracle Peoplesoft Enterprise Peopletools 8.59
Attack profile CVSS 3.1 · 6.5
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2021-28363.md and follow it. Check whether this project is affected by CVE-2021-28363. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- https://github.com/urllib3/urllib3/commit/8d65ea1ecf6e2cdc27d42124e587c1b83a3118b0
- https://github.com/urllib3/urllib3/commits/main
- https://github.com/urllib3/urllib3/security/advisories/GHSA-5phf-pp7p-vc2r
- https://www.oracle.com/security-alerts/cpuoct2021.html
- https://github.com/urllib3/urllib3/commit/8d65ea1ecf6e2cdc27d42124e587c1b83a3118b0
- https://github.com/urllib3/urllib3/commits/main
- https://github.com/urllib3/urllib3/security/advisories/GHSA-5phf-pp7p-vc2r
- https://www.oracle.com/security-alerts/cpuoct2021.html
References
- https://github.com/urllib3/urllib3/commit/8d65ea1ecf6e2cdc27d42124e587c1b83a3118b0
- https://github.com/urllib3/urllib3/commits/main
- https://github.com/urllib3/urllib3/security/advisories/GHSA-5phf-pp7p-vc2r
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/4S65ZQVZ2ODGB52IC7VJDBUK4M5INCXL/
- https://pypi.org/project/urllib3/1.26.4/
- https://security.gentoo.org/glsa/202107-36
- https://security.gentoo.org/glsa/202305-02
- https://security.netapp.com/advisory/ntap-20240621-0007/
- https://www.oracle.com/security-alerts/cpuoct2021.html
- https://github.com/urllib3/urllib3/commit/8d65ea1ecf6e2cdc27d42124e587c1b83a3118b0
- https://github.com/urllib3/urllib3/commits/main
- https://github.com/urllib3/urllib3/security/advisories/GHSA-5phf-pp7p-vc2r
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/4S65ZQVZ2ODGB52IC7VJDBUK4M5INCXL/
- https://pypi.org/project/urllib3/1.26.4/
- https://security.gentoo.org/glsa/202107-36
- https://security.gentoo.org/glsa/202305-02
- https://security.netapp.com/advisory/ntap-20240621-0007/
- https://www.oracle.com/security-alerts/cpuoct2021.html
- https://cert-portal.siemens.com/productcert/html/ssa-398330.html