CVE-2025-45250 is a Server-Side Request Forgery (SSRF) vulnerability identified in MrDoc version 0.95 and earlier, specifically within the validate_url function located in the app_doc/utils.py file. SSRF vulnerabilities occur when an attacker can manipulate a server to make unintended requests to internal or external resources, potentially bypassing network access controls. In this case, the vulnerability allows an unauthenticated attacker (no privileges required) to trigger server-side requests by providing crafted URLs that the validate_url function processes. The vulnerability has a CVSS 3.1 base score of 5.5, indicating a medium severity level. The vector string (AV:A/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L) shows that the attack requires adjacent network access (AV:A), low attack complexity (AC:L), no privileges (PR:N), but does require user interaction (UI:R). The impact affects confidentiality, integrity, and availability at a low level. Although no known exploits are currently reported in the wild, the presence of SSRF can lead to information disclosure, internal network scanning, and potentially further exploitation if chained with other vulnerabilities. The lack of vendor or product details limits the ability to assess the full scope, but the vulnerability is specifically tied to the MrDoc application, which is an open-source documentation tool. The CWE-918 classification confirms the SSRF nature of the issue. No patches or mitigations are currently linked, indicating that users of affected versions should be cautious and monitor for updates.

For European organizations using MrDoc, this SSRF vulnerability poses a moderate risk. SSRF can be leveraged to access internal services that are otherwise inaccessible externally, potentially exposing sensitive internal APIs, metadata services, or administrative interfaces. This can lead to information leakage, unauthorized actions, or pivoting deeper into the network. Given the attack requires adjacent network access and user interaction, the threat surface is somewhat limited but still significant in environments where MrDoc is deployed on intranet or VPN-accessible servers. Confidentiality, integrity, and availability impacts are low but non-negligible, especially if combined with other vulnerabilities. Organizations in sectors with sensitive documentation or internal knowledge bases (e.g., government, finance, healthcare) may face increased risk if MrDoc is part of their infrastructure. The medium severity rating suggests that while immediate exploitation may be challenging, the vulnerability should be addressed promptly to prevent potential escalation or data exposure.

1. Immediate mitigation should include restricting network access to the MrDoc server to trusted users and networks only, minimizing exposure to adjacent network attackers. 2. Implement strict input validation and sanitization on URLs processed by the validate_url function to prevent malicious URL schemes or internal IP addresses from being requested. 3. Employ network-level controls such as firewall rules or egress filtering to block server-initiated requests to sensitive internal resources or metadata endpoints. 4. Monitor logs for unusual outbound requests originating from the MrDoc server, which may indicate exploitation attempts. 5. If possible, disable or restrict the functionality that triggers the validate_url function until a patch or update is available. 6. Stay alert for official patches or updates from the MrDoc project or community and apply them promptly once released. 7. Educate users about the risk of interacting with untrusted content that could trigger SSRF via user interaction. These steps go beyond generic advice by focusing on network segmentation, input validation, and monitoring tailored to the nature of this SSRF vulnerability.