CVE-2021-22141 is a medium-severity vulnerability classified under CWE-601 (URL Redirection to Untrusted Site) affecting Elastic's Kibana software versions prior to 7.13.0 and 6.8.16. Kibana is a widely used open-source data visualization and exploration tool, part of the Elastic Stack, commonly deployed for monitoring, logging, and analytics. The vulnerability arises from an open redirect flaw that allows an attacker to craft a malicious URL which, when visited by an authenticated Kibana user, causes the application to redirect the user to an arbitrary external website. This behavior can be exploited in phishing attacks or to bypass security controls by making malicious URLs appear as legitimate Kibana links. The vulnerability requires the user to be logged in and to interact by clicking or visiting the crafted URL, but does not require any special privileges or authentication beyond the user’s existing session. The CVSS 3.1 base score is 6.1, reflecting network attack vector (AV:N), low attack complexity (AC:L), no privileges required (PR:N), user interaction required (UI:R), scope changed (S:C), and low impact on confidentiality and integrity (C:L, I:L) with no impact on availability (A:N). There are no known exploits in the wild reported to date. The vulnerability does not directly compromise system integrity or availability but can facilitate social engineering attacks and potentially lead to credential theft or session hijacking if combined with other vulnerabilities or attacker techniques. The flaw is remediated by upgrading Kibana to versions 7.13.0 or 6.8.16 and later, where input validation and redirect handling have been improved to prevent open redirects.

For European organizations, especially those relying heavily on Elastic Stack for operational monitoring, security analytics, or business intelligence, this vulnerability poses a moderate risk. While it does not allow direct system compromise or data exfiltration, the open redirect can be leveraged in targeted phishing campaigns to deceive authenticated users into visiting malicious sites, potentially leading to credential theft or malware infection. This risk is particularly relevant for organizations with large Kibana user bases, including IT administrators, security analysts, and data scientists. The impact is amplified in sectors with high regulatory requirements such as finance, healthcare, and critical infrastructure, where social engineering attacks can have cascading effects on data confidentiality and operational integrity. Additionally, since Kibana is often integrated with sensitive data sources, any compromise of user credentials or sessions facilitated by this vulnerability could indirectly lead to unauthorized access to sensitive information. The requirement for user interaction and authentication limits the scope but does not eliminate the risk, especially in environments where users may be less security-aware or where phishing defenses are weak.

1. Immediate upgrade of Kibana instances to version 7.13.0 or 6.8.16 or later to apply the official fix addressing the open redirect flaw. 2. Implement strict URL filtering and validation on any external links generated or shared from Kibana dashboards to prevent embedding malicious redirects. 3. Educate Kibana users on the risks of clicking on unexpected or suspicious URLs, especially those received via email or messaging platforms. 4. Deploy web proxy or gateway solutions capable of detecting and blocking known malicious URLs and redirect attempts. 5. Enable multi-factor authentication (MFA) for Kibana access to reduce the risk of credential compromise resulting from phishing. 6. Monitor Kibana access logs for unusual redirect patterns or spikes in user redirection events that could indicate exploitation attempts. 7. Where possible, restrict Kibana access to trusted networks or VPNs to reduce exposure to external phishing vectors. 8. Integrate Kibana with centralized security information and event management (SIEM) systems to correlate suspicious activities and respond promptly. These measures go beyond generic patching by focusing on user awareness, access control, and proactive monitoring to mitigate the social engineering risks posed by the vulnerability.