CVE-2025-49142 is a medium-severity vulnerability affecting Nautobot, a network source of truth and network automation platform widely used for managing network infrastructure. The vulnerability arises from improper neutralization of special elements in the Jinja2 templating engine used within Nautobot's computed fields, custom links, and similar features. Specifically, insufficient security configuration allows a malicious user to craft templates that can expose secret values stored in Nautobot or invoke Python APIs to modify data during template rendering. This can effectively bypass object-level permissions assigned to the viewing user, leading to unauthorized data disclosure and potential unauthorized modification of network configuration data. The vulnerability affects Nautobot versions prior to 1.6.32 and versions from 2.0.0 up to but not including 2.4.10. Nautobot versions 1.6.32 and 2.4.10 include fixes that address this issue by properly securing the templating feature. The vulnerability requires at least low privileges (PR:L) and no user interaction (UI:N), but has a high impact on confidentiality (VC:H) and a low impact on integrity (VI:L). The attack vector is network-based (AV:N) with high attack complexity (AC:H), indicating that exploitation requires some specialized knowledge or conditions. No known exploits are currently reported in the wild. Partial mitigation can be achieved by configuring object permissions to restrict template editing and rendering capabilities to trusted users only, limiting the attack surface until patches are applied.

For European organizations, this vulnerability poses a significant risk to the confidentiality and integrity of network automation data managed by Nautobot. Unauthorized disclosure of secrets such as API keys, credentials, or configuration parameters could lead to further compromise of network devices and infrastructure. Additionally, unauthorized modification of network data could disrupt network operations, causing outages or misconfigurations. Organizations relying on Nautobot for critical network automation and source of truth functions may face operational risks and compliance issues, especially under regulations like GDPR that mandate protection of sensitive data. The medium severity rating reflects the need for timely patching and access control hardening to prevent exploitation. Given the network-based attack vector, exposed Nautobot instances accessible over the internet or internal networks with insufficient segmentation are particularly at risk. The absence of known exploits suggests a window of opportunity for proactive defense.

1. Immediately upgrade Nautobot installations to version 1.6.32 or 2.4.10 or later, where the vulnerability is fixed. 2. Restrict permissions rigorously: limit the ability to create or modify templates, computed fields, and custom links to a minimal set of trusted administrators. 3. Review and audit existing templates for any suspicious or overly permissive configurations that could exploit the Jinja2 engine. 4. Implement network segmentation and firewall rules to restrict access to Nautobot management interfaces to trusted networks and users only. 5. Monitor logs for unusual template rendering activity or access patterns that could indicate exploitation attempts. 6. Educate administrators about the risks of template injection and the importance of secure configuration. 7. Consider deploying runtime application self-protection (RASP) or web application firewalls (WAF) with custom rules to detect and block suspicious template-related payloads. 8. Regularly back up Nautobot data and configuration to enable recovery in case of unauthorized modifications.