Is CVE-2021-21317 in the CISA KEV catalog?

No. CVE-2021-21317 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2021-21317?

CVE-2021-21317 has a CVSS v3 base score of 5.3 (MEDIUM).

What is the EPSS score for CVE-2021-21317?

CVE-2021-21317 has an EPSS score of 2.52% (83th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix CVE-2021-21317?

Upgrade uap-core to 0.11.0 or later.

CVE & CISA-KEV Catalog

CVE-2021-21317

MEDIUMEPSS 83th pctl

5.3

CVSS v3

NVD

Description

uap-core in an open-source npm package which contains the core of BrowserScope's original user agent string parser. In uap-core before version 0.11.0, some regexes are vulnerable to regular expression denial of service (REDoS) due to overlapping capture groups. This allows remote attackers to overload a server by setting the User-Agent header in an HTTP(S) request to maliciously crafted long strings. This is fixed in version 0.11.0. Downstream packages such as uap-python, uap-ruby etc which depend upon uap-core follow different version schemes.

CWE-400Resource Exhaustion CWE-1333

How to fix

Remediation Available

uap-coreNVD

Affected:< 0.11.0Fixed in:0.11.0CVE-2021-21317derived from NVD

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

ConfidentialityNone

IntegrityNone

AvailabilityLow

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

Exploit Intelligence

2.52%probability of exploitation in 30 days

83rdpercentile

Elevated risk: more likely to be exploited than 83% of all known CVEs.

References

Patch1

github.com

Third-Party Advisory2

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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.