CVE-2025-62763 is a Server-Side Request Forgery (SSRF) vulnerability identified in Zimbra Collaboration Server (ZCS) versions before 10.1.12. The root cause is the misconfiguration of the chat proxy component, which allows an attacker with low privileges to coerce the server into sending crafted requests to arbitrary internal or external endpoints. SSRF vulnerabilities enable attackers to bypass network access controls by leveraging the server as a proxy, potentially accessing sensitive internal resources not directly reachable from the internet. In this case, the vulnerability impacts the integrity of the system by allowing unauthorized requests that could manipulate internal services or APIs. The CVSS 3.1 vector (AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:L/A:N) indicates that the attack can be performed remotely over the network with low attack complexity, requires low privileges but no user interaction, and affects a scope beyond the vulnerable component, causing integrity loss without confidentiality or availability impact. Although no known exploits are currently reported in the wild, the presence of this vulnerability in widely used collaboration software poses a significant risk, especially in environments where internal network segmentation is critical. The lack of a patch link suggests that remediation involves upgrading to version 10.1.12 or later, which presumably addresses the chat proxy misconfiguration. Organizations relying on Zimbra Collaboration should prioritize this upgrade and audit their proxy configurations to prevent SSRF exploitation.

For European organizations, this SSRF vulnerability could lead to unauthorized internal network reconnaissance and manipulation of internal services, potentially compromising business processes and data integrity. While confidentiality and availability are not directly impacted, the ability to send unauthorized requests can facilitate lateral movement, privilege escalation, or indirect data manipulation. Organizations in sectors with strict data integrity requirements, such as finance, healthcare, and government, may face compliance and operational risks. The medium CVSS score reflects moderate risk, but the ease of remote exploitation with low privileges increases the urgency of mitigation. Given the collaborative nature of Zimbra, exploitation could also affect communication workflows, causing indirect operational disruptions. The absence of known exploits reduces immediate risk but does not eliminate the threat, especially as attackers often develop exploits after vulnerability disclosure. European entities with extensive internal network architectures and reliance on Zimbra Collaboration should consider this vulnerability a significant security concern.

1. Upgrade Zimbra Collaboration Server to version 10.1.12 or later, where the SSRF vulnerability is addressed. 2. Review and harden chat proxy configurations to restrict outbound requests only to trusted endpoints, implementing strict allowlists. 3. Implement network segmentation and firewall rules to limit the server's ability to reach sensitive internal resources. 4. Monitor server logs for unusual outbound request patterns indicative of SSRF exploitation attempts. 5. Employ web application firewalls (WAF) with SSRF detection capabilities to block suspicious requests. 6. Conduct regular security assessments and penetration testing focusing on SSRF vectors within collaboration platforms. 7. Educate administrators and security teams about SSRF risks and ensure timely application of security updates. 8. If immediate upgrade is not feasible, consider disabling or restricting chat proxy features temporarily to reduce attack surface.