Is CVE-2021-3909 in the CISA KEV catalog?

No. CVE-2021-3909 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2021-3909?

CVE-2021-3909 has a CVSS v3 base score of 4.4 (MEDIUM).

What is the EPSS score for CVE-2021-3909?

CVE-2021-3909 has an EPSS score of 1.51% (71th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix CVE-2021-3909?

Upgrade cfrpki on debian 11 to 1.4.2-1~deb11u1 or later.

CVE & CISA-KEV Catalog

CVE-2021-3909

MEDIUMEPSS 71th pctl

4.4

CVSS v3

NVD

Description

OctoRPKI does not limit the length of a connection, allowing for a slowloris DOS attack to take place which makes OctoRPKI wait forever. Specifically, the repository that OctoRPKI sends HTTP requests to will keep the connection open for a day before a response is returned, but does keep drip feeding new bytes to keep the connection alive.

CWE-400Resource Exhaustion

How to fix

Remediation Available

cfrpkiDebian

Fixed in:1.4.2-1~deb11u1CVE-2021-3909

Fixed in:1.4.0-1CVE-2021-3909

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 ComplexityHigh

Privileges RequiredHigh

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityNone

IntegrityNone

AvailabilityHigh

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

Exploit Intelligence

1.51%probability of exploitation in 30 days

71stpercentile

Elevated risk: more likely to be exploited than 71% of all known CVEs.

References

Third-Party Advisory3

Related Vulnerabilities

Other CWE-400 (Resource Exhaustion) vulnerabilities, ordered by exploit likelihood. View all

CVE	Severity	CVSS	EPSS	Exploited	Fix
CVE-2023-44487	High	7.5	100%	KEV	Fix
CVE-2021-44228	Critical	10.0	100%	KEV + Ransom	Fix
CVE-2011-3192	High	7.8	99%	-	Fix
CVE-2019-11478	Medium	5.3	95%	-	Fix
CVE-2024-25617	Medium	5.3	89%	-	Fix
CVE-2018-1000115	High	7.5	89%	-	Fix

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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.