CVE-2025-13647 in Identity Server
Summary
by MITRE • 11/02/2026
The affected component fails to enforce expected validation constraints on the `content-type` header when processing certain requests. This allows an attacker to submit a crafted request with a manipulated `content-type` header.
Successful exploitation can lead to the unintended exposure of the file paths for certificate files. This information disclosure could potentially be leveraged in subsequent attacks or compromise the confidentiality of the system.
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Analysis
by VulDB Data Team • 11/02/2026
The identified vulnerability stems from an insufficient validation mechanism within the application's request processing logic, specifically concerning the handling of the HTTP content-type header. In a secure implementation, server-side components must strictly enforce expected data formats and types to ensure that incoming requests are processed according to predefined security policies. However, in this scenario, the affected component fails to validate or sanitize the content-type value provided by the client before processing subsequent request parameters. This lack of enforcement creates an opening for attackers to manipulate how the server interprets the payload structure, potentially bypassing internal routing or parsing rules that rely on accurate header information to determine file access permissions or data handling procedures.
By submitting a crafted HTTP request with a manipulated content-type header, an attacker can exploit this misconfiguration to trigger unintended behavior within the application's backend logic. The core technical flaw lies in the assumption that the client-provided metadata accurately reflects the actual structure of the transmitted data. When this assumption is violated due to weak validation, the server may proceed with operations intended for different content types or fail to apply appropriate security controls associated with specific file formats. This discrepancy allows the attacker to influence the internal state of the application in ways that were not anticipated by the developers, leading to a breakdown in the expected separation between user input and system resource access.
The operational impact of this vulnerability is significant, primarily manifesting as an information disclosure flaw. Successful exploitation results in the unintended exposure of sensitive file paths associated with certificate files on the underlying operating system or application directory structure. Certificate files often contain critical cryptographic material, including private keys or configuration details that are essential for secure communications. The revelation of these specific file paths provides attackers with valuable reconnaissance data, enabling them to map the server's architecture and identify potential targets for further exploitation. This exposure compromises the confidentiality aspect of the system's security posture by revealing internal implementation details that should remain hidden from external entities.
This vulnerability aligns closely with CWE-209, which describes the generation of error messages containing sensitive information, although in this case, it manifests as path disclosure rather than a direct stack trace or debug output. It also relates to CWE-770, specifically regarding allocation of resources without limits or constraints, where the system fails to restrict access based on input validation. From an offensive security perspective, such flaws are often categorized under ATT&CK technique T1083, which involves file and directory discovery. The ability to enumerate sensitive paths is a critical precursor step in many attack chains, as it allows adversaries to locate high-value targets for subsequent attacks such as local privilege escalation or remote code execution if other vulnerabilities exist within those specific files or their associated services.
To mitigate this risk, immediate remediation efforts should focus on implementing strict input validation and sanitization routines for all HTTP headers, particularly the content-type field. The application must enforce a whitelist of acceptable content types rather than relying on blacklist approaches or trusting client-supplied values implicitly. Additionally, developers should ensure that error handling mechanisms do not leak internal file system paths to end-users or API consumers. Implementing robust access control checks that verify permissions before any file operation is executed can further reduce the attack surface. Regular security testing, including dynamic application security scanning and manual penetration testing focused on header manipulation, will help identify similar validation gaps in other parts of the codebase.