CVE-2026-28508 in Idno
Summary
by MITRE • 03/06/2026
Idno is a social publishing platform. Prior to version 1.6.4, a logic error in the API authentication flow causes the CSRF protection on the URL unfurl service endpoint to be trivially bypassed by any unauthenticated remote attacker. Combined with the absence of a login requirement on the endpoint itself, this allows an attacker to force the server to make arbitrary outbound HTTP requests to any host, including internal network addresses and cloud instance metadata services, and retrieve the response content. This issue has been patched in version 1.6.4.
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Analysis
by VulDB Data Team • 03/16/2026
The vulnerability identified as CVE-2026-28508 affects the Idno social publishing platform and represents a critical logic error in the API authentication flow that undermines fundamental security controls. This issue specifically targets the URL unfurl service endpoint, which is designed to fetch and display metadata from external URLs. The flaw lies in the CSRF protection mechanism that should have prevented unauthorized requests from being processed by the service, yet the implementation contains a critical oversight that allows any remote attacker to bypass these security measures without authentication. The vulnerability exists in versions prior to 1.6.4, indicating that the developers were aware of the issue and implemented a fix in their subsequent release.
The technical exploitation of this vulnerability stems from the combination of two distinct security weaknesses that together create a dangerous attack vector. First, the CSRF protection mechanism fails to properly validate incoming requests, making it trivial for attackers to craft malicious requests that appear to be legitimate. Second, the endpoint lacks proper authentication requirements, meaning that even if CSRF protection were functioning correctly, the absence of login validation would still allow unauthorized access. This dual failure creates a scenario where attackers can leverage the URL unfurl service to make arbitrary outbound HTTP requests to any destination, including internal network resources and cloud metadata services that typically contain sensitive information.
The operational impact of this vulnerability extends far beyond simple data exfiltration, as it provides attackers with the ability to perform reconnaissance and potentially escalate their attacks within the target network. By forcing the server to make outbound requests to internal addresses, attackers can map network topology, identify internal services, and potentially discover vulnerable systems that are not directly exposed to the internet. The ability to access cloud instance metadata services represents a particularly severe risk, as these services often contain sensitive credentials, instance identifiers, and other information that can be used for further compromise. The vulnerability effectively transforms the Idno server into an unwitting proxy for network reconnaissance and attack delivery, making it a valuable tool for threat actors seeking to expand their access within compromised environments.
This vulnerability aligns with several cybersecurity frameworks and threat modeling approaches, particularly those addressing weak session management and insufficient input validation as outlined in CWE-352 for Cross-Site Request Forgery and CWE-284 for Improper Access Control. The attack pattern follows the techniques described in the MITRE ATT&CK framework under the T1046 category for Network Service Scanning, where adversaries use compromised systems to map network topology and identify potential targets. The flaw also demonstrates characteristics of T1566 related to credential access through service exploitation, as attackers can potentially gain access to sensitive information through the metadata services that the vulnerable endpoint can reach. Organizations should consider implementing network segmentation, outbound traffic filtering, and monitoring for unusual HTTP requests to mitigate the risk of exploitation. The patch in version 1.6.4 likely addresses both the CSRF validation logic and ensures proper authentication requirements are enforced on the vulnerable endpoint, restoring the intended security controls that protect against unauthorized access and outbound request manipulation.