Server-Side Request Forgery (SSRF) in Apache Solr - CVE-2021-27905
Published: April 13, 2021 / Updated: November 20, 2022
Vulnerability identifier: #VU52060
CSH Severity: Medium
CVSS v4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:L/SI:N/SA:N]
CVE-ID: CVE-2021-27905
CWE-ID: CWE-918
Exploitation vector: Remote access
Exploit availability:
Public exploit is available
Vulnerability details
The disclosed vulnerability allows a remote attacker to perform SSRF attacks.
The vulnerability exists due to insufficient validation of user-supplied input passed via the "masterUrl" or "leaderUrl" parameters to "/replication" URL. A remote attacker can send a specially crafted HTTP request and trick the application to initiate requests to arbitrary systems.
Successful exploitation of this vulnerability may allow a remote attacker gain access to sensitive data, located in the local network or send malicious requests to other servers from the vulnerable system.
Affected software
Apache Solr
How to mitigate CVE-2021-27905
Install updates from vendor's website.
Apache Solr - update to 8.8.2
Links to Public Exploits and PoC-codes
- Exploit #8617 - CVE-2021-27905.POC (POC for LFI related to CVE-2021-27905) (November 20, 2022)
- Exploit #6613 - CVE-2021-27905 ([CVE-2021-27905] Apache Solr ReplicationHandler Server Side Request Forgery (SSRF)) (August 11, 2021)
- Exploit #5544 - Solr-SSRF (Apache Solr SSRF(CVE-2021-27905)) (June 9, 2021)