CVE-2025-14896 in kroki
Summary
by MITRE • 12/18/2025
due to insufficient sanitazation in Vega’s `convert()` function when `safeMode` is enabled and the spec variable is an array. An attacker can craft a malicious Vega diagram specification that will allow them to send requests to any URL, including local file system paths, leading to exposure of sensitive information.
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Analysis
by VulDB Data Team • 12/18/2025
The vulnerability identified as CVE-2025-14896 represents a critical security flaw in the Vega visualization library's `convert()` function that operates under safeMode restrictions. This issue arises from inadequate input sanitization when processing Vega diagram specifications where the spec variable is structured as an array. The vulnerability exists within the defensive mechanisms designed to prevent unauthorized access patterns, creating an exploitable condition that undermines the intended security boundaries. The flaw specifically manifests when the safeMode parameter is enabled, which should normally restrict access to local resources and external endpoints, but fails to properly validate array-based specification inputs.
The technical implementation of this vulnerability stems from the improper handling of array data structures within the conversion pipeline of Vega's processing engine. When an attacker provides a malicious Vega specification containing an array-based spec parameter, the sanitization logic fails to adequately filter or validate the contents of this array structure. This allows arbitrary URL requests to be constructed and executed through the vulnerable conversion function, bypassing the normal security restrictions that should prevent access to local file system paths and internal network resources. The vulnerability operates at the intersection of data validation and access control mechanisms, where the array processing logic does not properly account for the potential for malicious content within array elements.
The operational impact of this vulnerability is severe and multifaceted, as it enables attackers to perform unauthorized data exfiltration and reconnaissance activities. An attacker can construct malicious Vega specifications that, when processed through the vulnerable `convert()` function, will attempt to access local file system paths, internal network endpoints, or other sensitive resources that should normally be restricted. This capability allows for information disclosure attacks where sensitive files, configuration data, or system information can be retrieved from the target system. The vulnerability essentially provides a means to circumvent network segmentation and access control policies, potentially leading to broader system compromise and data breaches.
Security mitigations for this vulnerability should focus on implementing comprehensive input validation and sanitization measures within the Vega library's processing pipeline. The most effective approach involves strengthening the array handling logic within the `convert()` function to ensure that all array elements are properly validated and sanitized before being processed. This includes implementing strict type checking, content validation, and access restriction enforcement for all array-based inputs. Organizations should also consider implementing network-level controls and monitoring to detect unusual outbound requests that may indicate exploitation attempts. The remediation efforts should align with security best practices outlined in the CWE framework, specifically addressing CWE-20: Improper Input Validation and CWE-913: Improper Control of Dynamically-Managed Code Resources. Additionally, this vulnerability may be categorized under ATT&CK technique T1071.004: Application Layer Protocol: DNS, as it enables unauthorized network communication through the visualization library's processing functions.