Description

Improper Control of Generation of Code ('Code Injection') vulnerability in Apache Syncope. An administrator with adequate entitlements for Implementations can create a malicious Groovy Command class containing untrusted code in their CommandArgs static implementation, bypassing the Groovy security sandbox. 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": "6.5",
  "pubDate": "2026-09-14T13:18:46.490Z",
  "pubdate": "2026-09-14T13:18:46.490Z",
  "executiveSummary": "This vulnerability, classified as Improper Control of Generation of Code ('Code Injection'), affects multiple versions of Apache Syncope. The flaw resides within the implementation handling mechanism, specifically concerning the Groovy scripting environment.\nThe vulnerability allows an authenticated administrator with entitlements for 'Implementations' to bypass the configured Groovy security sandbox. By crafting a malicious Groovy Command class and embedding untrusted code within the CommandArgs static implementation, an attacker can execute arbitrary code on the underlying host system.\nThe exploit requires administrative privileges, specifically the entitlement to manage implementations, making it a critical risk for internal security models. Successfully executing this attack leads to full remote code execution, granting the attacker the ability to perform unauthorized system operations, exfiltrate sensitive data, or compromise the integrity of the Apache Syncope instance.\nAffected software includes 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. Organizations are strongly advised to upgrade to versions 4.0.8 or 4.1.3 to remediate this security deficiency.",
  "technicalDetails": "The vulnerability originates from an insecure design choice in how Apache Syncope processes user-defined 'Implementations' written in Groovy. The framework provides a mechanism to extend functionality via custom Groovy scripts; however, the validation logic fails to sufficiently restrict the construction of class definitions within these scripts.\nThe core issue lies in the handling of the CommandArgs static implementation. When an administrator creates or updates an implementation, the application fails to enforce the Groovy security sandbox limitations during the compilation or instantiation phase of the Command class. Specifically, the static block or the static implementation details of the provided Groovy class can be used to encapsulate malicious logic that executes outside the expected sandboxed environment.\nAttack Flow: 1. Authentication and Authorization: The attacker must authenticate to the Apache Syncope administrative console with sufficient entitlements to modify or create 'Implementations'. 2. Payload Preparation: The attacker defines a malicious Groovy class. Within the CommandArgs static implementation, the attacker injects arbitrary Java/Groovy code capable of interacting with system resources. 3. Injection: The malicious script is saved through the Implementations management interface. 4. Triggering: The application attempts to load or execute the defined Command class, at which point the malicious code within the static implementation is evaluated and executed by the JVM hosting the Syncope application.\nBy bypassing the security sandbox, the attacker effectively elevates their execution context. Because the code runs within the same process space as the Apache Syncope application, the payload inherits the application's system permissions. This allows for arbitrary command execution, file system access, and potential lateral movement within the network environment.\nThe vulnerability is restricted to users who already possess administrative privileges for managing system implementations. Therefore, the risk is highest in environments where administrative credentials may be compromised or where internal malicious insiders are a threat vector. The lack of robust bytecode or AST (Abstract Syntax Tree) transformation validation when compiling the provided Groovy scripts allows this sandbox escape, as the underlying platform trusts the input provided by an administrator without applying strict execution policies to the class initialization phase."
}