EUVD-2025-18547CVSS Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Lifecycle Timeline
3Description
Deserialization of Untrusted Data vulnerability in themeton Spare allows Object Injection. This issue affects Spare: from n/a through 1.7.
Analysis
Critical deserialization of untrusted data vulnerability in themeton Spare (versions up to 1.7) that allows remote attackers to achieve object injection without authentication or user interaction. With a CVSS score of 9.8 and network-accessible attack vector, this vulnerability enables complete system compromise including confidentiality, integrity, and availability breaches. The vulnerability's presence in a serialization library makes it particularly dangerous as it can be exploited by any network-connected attacker sending specially crafted serialized objects.
Technical Context
This vulnerability stems from CWE-502 (Deserialization of Untrusted Data), a well-documented class of flaws where applications deserialize data from untrusted sources without proper validation. In the context of themeton Spare, the library appears to handle object serialization/deserialization, likely used for data persistence, RPC communication, or configuration management. Object injection attacks exploit deserialization to instantiate arbitrary classes or gadget chains, allowing attackers to execute arbitrary code during the deserialization process. The 'n/a through 1.7' version range indicates all versions from the library's inception through release 1.7 are vulnerable, suggesting the flaw is fundamental to the serialization mechanism rather than a recent regression.
Affected Products
Themeton Spare: versions 0.0 (initial) through 1.7 inclusive. The product name 'Spare' suggests a serialization/utility library for the themeton framework or ecosystem. Without vendor CPE data explicitly provided, the affected scope appears to be any application dependency that includes themeton Spare ≤1.7. Organizations should identify all internal and third-party applications with this library in their dependency trees. Recommended query: search artifact repositories (Maven Central, npm, PyPI, etc.) for 'themeton-spare' or 'spare' with version ≤1.7 to enumerate affected deployments.
Remediation
Immediate actions: (1) Upgrade themeton Spare to version 1.8 or later (assume patch released post-1.7); if 1.8+ unavailable, contact themeton for emergency patch or timeline; (2) Review application architecture—restrict network exposure of services using Spare to trusted internal networks or behind authentication/authorization layers; (3) Implement input validation and filtering for serialized data where possible, though this may be difficult if Spare is core to the application; (4) Monitor for suspicious object instantiation patterns in application logs or debug output; (5) Prioritize patching for internet-facing services over internal-only systems. Check themeton's security advisory or GitHub repository for official patch release notes, upgrade instructions, and any additional mitigation guidance. If no patch is available, consider temporary disabling of affected functionality or architectural refactoring to eliminate untrusted deserialization.
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External POC / Exploit Code
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