CVE-2021-27905 : What You Need to Know
Learn about CVE-2021-27905, an SSRF vulnerability in Apache Solr ReplicationHandler impacting versions before 8.8.2. Understand the impact, affected systems, and mitigation steps.
Apache Solr has been identified with an SSRF vulnerability in the ReplicationHandler affecting versions prior to 8.8.2.
Understanding CVE-2021-27905
This CVE involves an SSRF vulnerability found in the ReplicationHandler component of Apache Solr.
What is CVE-2021-27905?
The ReplicationHandler in Apache Solr has a parameter that allows an attacker to designate another ReplicationHandler on a different core, potentially leading to SSRF vulnerability.
The Impact of CVE-2021-27905
This issue can be exploited by attackers to perform unauthorized actions by accessing internal resources and services.
Technical Details of CVE-2021-27905
The vulnerability arises from a lack of proper validation in the "masterUrl" parameter in the ReplicationHandler, making it susceptible to SSRF attacks.
Vulnerability Description
The SSRF vulnerability allows attackers to direct the ReplicationHandler to access unauthorized URLs, potentially leading to information disclosure or data manipulation.
Affected Systems and Versions
All versions of Apache Solr before 8.8.2 are impacted by this vulnerability.
Exploitation Mechanism
Attackers can exploit this vulnerability by manipulating the "masterUrl" parameter to fetch arbitrary data from internal resources.
Mitigation and Prevention
It is essential to take immediate action to prevent exploitation of this vulnerability.
Immediate Steps to Take
Ensure that all access to the ReplicationHandler is restricted to internal usage only to mitigate the SSRF risk.
Long-Term Security Practices
Regularly update Apache Solr to the latest version to patch known vulnerabilities and enhance system security.
Patching and Updates
Apply the patch provided by Apache Software Foundation for Apache Solr version 8.8.2 to remediate CVE-2021-27905.