CVE-2021-27905
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.
- Affected products
- Apache Solr
- Apache Solr
- < 8.8.2
- Fix
- Available
- CVSS 3.1
- 9.8 CRITICAL
- EPSS
- 93.1% (100th percentile)
- Weakness
- CWE-918
- NVD status
- Modified
- Published
- 2021-04-13
Workaround
Ensure that any access to the replication handler is purely internal to Solr. Typically, it's only accessed externally for diagnostic/informational purposes.
10 known exploits for CVE-2021-27905
Proof-of-concept code and exploit modules indexed by Sploitus