Description

Incorrect Authorization vulnerability in Apache Syncope. An administrator with adequate entitlements in a given Realm may be able to read via REST the full Connector configuration, confidential properties included, scoped in another Realm and thus be able to effectively duplicate such Connector instance into the Realm they have administration rights for. This issue affects Apache Syncope: from 3.0.0-M0 through 3.0.16, from 4.0.0-M0 Through 4.0.7, from 4.1.0-M0 through 4.1.2. Users are recommended to upgrade to version 4.0.8 / 4.1.3, which fix this issue.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "9.8",
  "pubDate": "2026-09-14T13:18:45.437Z",
  "pubdate": "2026-09-14T13:18:45.437Z",
  "executiveSummary": "This vulnerability is an Incorrect Authorization flaw within Apache Syncope, categorized as an improper access control issue. It allows an administrator with legitimate privileges in one Realm to circumvent security boundaries and access the full REST-based Connector configuration of a different, unauthorized Realm.\nThe primary risk is the exposure of sensitive, confidential properties—such as administrative credentials, database connection strings, or secret API keys—embedded within Connector configurations. This level of unauthorized access grants an attacker the ability to exfiltrate critical infrastructure data and replicate specialized Connector instances into their own managed Realms, potentially leading to privilege escalation, lateral movement, or complete compromise of integrated external systems.\nThe vulnerability affects Apache Syncope versions 3.0.0-M0 through 3.0.16, 4.0.0-M0 through 4.0.7, and 4.1.0-M0 through 4.1.2. The exploitation requires existing administrative entitlements within at least one Realm, which is then abused to perform out-of-scope read operations. There are no requirements for external network exposure, as the attack is executed through the internal REST API. Remediation requires upgrading to the specified patched versions, where authorization logic has been corrected to properly enforce inter-realm access restrictions.",
  "technicalDetails": "The vulnerability resides within the Apache Syncope REST API authorization handling logic, which fails to correctly validate the scope of a request when retrieving Connector configuration objects. In Apache Syncope, administrative control is partitioned by Realms; however, the API endpoints responsible for exposing Connector instances do not adequately verify if the requesting administrator’s entitlements strictly correspond to the Realm associated with the requested configuration.\nThe root cause is a deficiency in the authorization interceptors or access control checks that govern the REST services. Specifically, when an administrative user initiates a request to read the details of a Connector instance, the system incorrectly trusts the identifier passed in the request without enforcing a strict cross-realm validation check. Because the Connector configuration objects contain 'confidential' properties—which are typically handled with heightened security—the ability to read these objects across Realm boundaries constitutes a significant security breach.\nThe attack flow follows a predictable pattern: 1) The attacker, possessing valid credentials and administrative privileges for 'Realm A', targets the REST endpoint associated with Connector management. 2) The attacker crafts a request aimed at an object belonging to 'Realm B', for which they possess no authorized scope. 3) The backend service processes the request, failing to identify that the target object is outside the authenticated user's authorization boundary. 4) The REST service returns the full, serialized Connector configuration, including plain-text sensitive attributes or encrypted properties for which the attacker can potentially derive keys.\nOnce the configuration is retrieved, the attacker gains the ability to duplicate the Connector instance into 'Realm A'. By mirroring the configuration, the attacker effectively gains the same operational capabilities provided by the Connector in 'Realm B', such as connecting to unauthorized third-party systems or databases managed by the target Realm. This bypass allows the attacker to move beyond the restrictions of their initial administrative partition, effectively escalating their access to data and resources that are meant to be isolated.\nAffected versions include the 3.0.x branch (3.0.0-M0 to 3.0.16), the 4.0.x branch (4.0.0-M0 to 4.0.7), and the 4.1.x branch (4.1.0-M0 to 4.1.2). The vulnerability does not require remote network exploitation; it is an internal privilege abuse scenario where the internal authorization mechanism is bypassed via legitimate API calls. Post-exploitation, the attacker maintains a persistent foothold by successfully duplicating the Connector, allowing them to leverage the stolen configuration for further unauthorized system integrations."
}