Is CVE-2021-27905 in the CISA KEV catalog?

No. CVE-2021-27905 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2021-27905?

CVE-2021-27905 has a CVSS v3 base score of 9.8 (CRITICAL).

What is the EPSS score for CVE-2021-27905?

CVE-2021-27905 has an EPSS score of 93.05% (100th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix CVE-2021-27905?

Upgrade lucene-solr on debian 11 to 3.6.2+dfsg-23 or later.

CVE & CISA-KEV Catalog

CVE-2021-27905

CRITICALEPSS 100th pctl

9.8

CVSS v3

NVD

Description

The ReplicationHandler (normally registered at "/replication" under a Solr core) in Apache Solr has a "masterUrl" (also "leaderUrl" alias) parameter that is used to designate another ReplicationHandler on another Solr core to replicate index data into the local core. To prevent a SSRF vulnerability, Solr ought to check these parameters against a similar configuration it uses for the "shards" parameter. Prior to this bug getting fixed, it did not. This problem affects essentially all Solr versions prior to it getting fixed in 8.8.2.

CWE-918Server-Side Request Forgery (SSRF)

How to fix

Remediation Available

lucene-solrDebian

Fixed in:3.6.2+dfsg-23CVE-2021-27905

TridentStack Control can deploy fixes like this automatically across your Windows, macOS, and Linux fleet. See how it works

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

ConfidentialityHigh

IntegrityHigh

AvailabilityHigh

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

Exploit Intelligence

93.05%probability of exploitation in 30 days

100thpercentile

Very high risk: more likely to be exploited than 100% of all known CVEs.

References

Vendor Advisory1

lists.apache.org

Third-Party Advisory1

security.netapp.com

Other references10

Related Vulnerabilities

Other CWE-918 (Server-Side Request Forgery (SSRF)) vulnerabilities, ordered by exploit likelihood. View all

CVE	Severity	CVSS	EPSS	Exploited	Fix
CVE-2024-21893	High	8.2	100%	KEV + Ransom	-
CVE-2021-40438	Critical	9.0	100%	KEV	Fix
CVE-2021-34473	Critical	9.1	100%	KEV + Ransom	Fix
CVE-2021-26855	Critical	9.1	100%	KEV + Ransom	Fix
CVE-2021-21985	Critical	9.8	100%	KEV + Ransom	Fix
CVE-2022-41040	High	8.8	100%	KEV + Ransom	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.