CVE-2026-102138 in Kiteworks
Summary
by MITRE • 10/01/2026
An authenticated administrator on a node with an optional, separately licensed gateway role enabled could supply a connector URL that the server retrieved without sufficient validation of its scheme or destination, causing the server to issue requests to internal network services. Exploitation requires the licensed gateway role to be active.
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Analysis
by VulDB Data Team • 10/01/2026
The vulnerability described constitutes a Server-Side Request Forgery (SSRF) flaw within an administrative interface that relies on user-supplied input for connector configuration. This specific instance is notable because it targets systems where a separately licensed gateway role has been enabled, indicating that the attack surface is restricted to authenticated administrators who possess elevated privileges and access to this specific feature set. The core technical deficiency lies in the server's handling of the provided URL during the retrieval process. Instead of enforcing strict validation rules regarding the Uniform Resource Identifier (URI) scheme or validating the destination IP address against a whitelist, the application blindly trusts the input. This lack of sanitization allows an attacker to manipulate the request origin, effectively turning the vulnerable service into a proxy that can reach internal network resources that are otherwise inaccessible from external networks.
From a technical perspective, this flaw aligns with CWE-918, which defines Server-Side Request Forgery as a vulnerability where a web server retrieves a specified resource on behalf of a user without validating the requested URL's destination or scheme. In typical SSRF scenarios, attackers exploit these flaws to perform port scanning, access sensitive internal APIs, or interact with cloud metadata services that contain authentication credentials for other infrastructure components. The requirement for an authenticated administrator significantly raises the barrier to entry compared to unauthenticated SSRFs but does not eliminate the risk. An insider threat actor or a compromised administrative account can leverage this capability to pivot laterally within the network architecture. By crafting requests to internal endpoints, such as localhost services, database ports, or management interfaces of other nodes in the cluster, an attacker can gather intelligence about the internal topology and identify further vulnerabilities for exploitation.
The operational impact of this vulnerability is severe due to its potential role in broader attack chains. Once an administrator account is compromised, the ability to issue requests to internal network services facilitates reconnaissance and lateral movement. Attackers may use this functionality to probe for open ports on internal hosts, attempt to access unauthenticated administrative panels running on private IP addresses, or extract sensitive data from internal APIs that lack proper authentication mechanisms. This capability undermines the principle of least privilege by allowing a single compromised account to act as a bridge between the external-facing application and the protected internal network segment. The presence of the licensed gateway role suggests this system is part of a larger distributed architecture, meaning successful exploitation could potentially impact multiple nodes or services within that environment, leading to data exfiltration, service disruption, or complete infrastructure compromise depending on what internal resources are reachable.
Mitigation strategies must focus on strict input validation and network segmentation controls. The most effective technical fix involves implementing allow-listing for the connector URL scheme, permitting only safe protocols such as HTTP and HTTPS while rejecting dangerous schemes like file, gopher, or dict that could be used to access local files or interact with other services directly. Additionally, destination IP address validation is critical; the server should resolve the hostname of any provided URL and verify that the resulting IP address does not fall within private ranges (such as 10.x.x.x, 172.16-31.x.x, or 192.168.x.x) or loopback addresses before issuing the request. If possible, implementing a dedicated proxy layer with strict egress filtering can further isolate internal services from direct access by application servers. From an organizational standpoint, ensuring that the gateway role is only enabled when strictly necessary reduces the attack surface. Regular audits of administrative accounts and monitoring for unusual outbound connection patterns to internal IP ranges can also aid in detecting potential exploitation attempts before significant damage occurs. This vulnerability maps directly to MITRE ATT&CK technique T1598, specifically Phishing for Inbound Connections or SSRF variants where an attacker uses the application as a proxy to access internal resources.