CVE-2021-27905
SSRF vulnerability with the Replication handler
CRITICAL 9.8EPSS 93.1%
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
- Apache Software Foundation · Apache Solr
- CVSS v3.1 NVD
- 9.8 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - CVSS v3.1 GitHub
- 7.1 HIGH
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:N - CVSS v2.0 NVD
- 7.5 HIGH
AV:N/AC:L/Au:N/C:P/I:P/A:P - EPSS
- 93.05% chance of exploitation in the next 30 days, 100th percentile
- Nuclei
- critical · CWE-918
- Published
- 2021-04-13
- Updated
- 2024-08-03
Proof-of-concept exploits (4)
- W2Ning/Solr-SSRF0★ · 2021-04-28
- murataydemir/CVE-2021-279056★ · 2021-08-10
- pdelteil/CVE-2021-27905.POC3★ · 2022-11-17
- RIZZZIOM/CVE-2021-279052★ · 2025-12-17
Nuclei templates (1)
Exploit collections (2)
- Apache Solr Replication handler SSRF（CVE-2021-27905）.mdtzwlhack/Vulnerability
- CVE-2021-27905.yamlzan8in/afrog
Security advisories
- https://lists.apache.org/thread.html/r0ddc3a82bd7523b1453cb7a5e09eb5559517145425074a42eb3…
- https://security.netapp.com/advisory/ntap-20210611-0009
- advisories/GHSA-5phw-3jrp-3vj8