Is CVE-2021-28363 in the CISA KEV catalog?

No. CVE-2021-28363 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2021-28363?

CVE-2021-28363 has a CVSS v3 base score of 6.5 (MEDIUM).

What is the EPSS score for CVE-2021-28363?

CVE-2021-28363 has an EPSS score of 2.11% (80th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix CVE-2021-28363?

Upgrade python-urllib3 on debian 11 to 1.26.4-1 or later.

CVE & CISA-KEV Catalog

CVE-2021-28363

MEDIUMEPSS 80th pctl

6.5

CVSS v3

NVD

Description

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.

CWE-295Improper Certificate Validation

How to fix

Remediation Available

python-urllib3Debian

Fixed in:1.26.4-1CVE-2021-28363

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredNone

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityLow

IntegrityLow

AvailabilityNone

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

Exploit Intelligence

2.11%probability of exploitation in 30 days

80thpercentile

Elevated risk: more likely to be exploited than 80% of all known CVEs.

References

Patch3

Mitigation1

github.com

Third-Party Advisory2

Other references3

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2024-11-21.