CVE-2021-27905 - CVE House
Back to Database
Status published Critical CVE-2021-27905

SSRF vulnerability with the Replication handler

Vulnerability 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.

Impact Analysis

Refer to official advisory for detailed impact metrics.

Remediation

Ensure systems are updated to the latest vendor-supplied patch levels.

THREAT MONITOR

Am I Vulnerable?

Launch our assessment wizard to check if your infrastructure is exposed to • CVE-2021-27905

Credits & Attribution

The following person or organization is credited with identifying this vulnerability, as recorded in the NVD database:

  • Reported by Caolinhong(Skay) from QI-ANXIN Cert (QI-ANXIN Technology Group Inc.)

Affected Vendor

Apache Software Foundation

View all reports →

Affected Software

Apache Solr
Vulnerable Versions:
Apache Solr

Timeline

Official Publish: April 13th, 2021
Last Modified: August 3rd, 2024
Added to House: July 21st, 2026

CVSS Vectors

V3: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Weaknesses (CWE)