CVE-2025-41077: Viafirma Inbox Auth Bypass Vulnerability

CVE-2025-41077 Overview

An Insecure Direct Object Reference (IDOR) vulnerability has been discovered in Viafirma Inbox v4.5.13 that allows any authenticated user without privileges in the application to list all users, access and modify their data. This vulnerability enables attackers to modify user email addresses and subsequently use the password recovery functionality to access the application by impersonating any user, including those with administrative permissions.

Critical Impact

Low-privileged authenticated attackers can escalate to administrative access by exploiting IDOR to modify user email addresses and hijack accounts through password recovery flows.

Affected Products

• Viafirma Inbox v4.5.13

Discovery Timeline

• 2026-01-12 - CVE-2025-41077 published to NVD
• 2026-01-13 - Last updated in NVD database

Technical Details for CVE-2025-41077

Vulnerability Analysis

This vulnerability is classified as CWE-639 (Authorization Bypass Through User-Controlled Key), commonly known as an Insecure Direct Object Reference (IDOR). The flaw exists in Viafirma Inbox's access control implementation, where the application fails to properly validate whether an authenticated user has authorization to access or modify resources belonging to other users.

The attack chain is particularly dangerous because it combines two exploitation phases: first, the attacker enumerates and accesses user data through the IDOR vulnerability, then leverages this access to modify email addresses. The second phase weaponizes the legitimate password recovery mechanism to complete account takeover, allowing full impersonation of any user including administrators.

Root Cause

The root cause stems from missing authorization checks when processing user data requests. The application relies solely on authentication status rather than implementing proper object-level authorization controls. When an authenticated user makes requests to access or modify user records, the system fails to verify whether the requesting user has the necessary permissions to interact with the targeted resource.

Attack Vector

The vulnerability is exploitable over the network by any authenticated user, regardless of their privilege level within the application. The attack requires no user interaction and can be automated to enumerate all users in the system.

An attacker would typically:

1. Authenticate to Viafirma Inbox with any valid low-privilege account
2. Manipulate object identifiers in API requests to enumerate and access other user records
3. Modify the target user's email address to an attacker-controlled address
4. Trigger the password recovery functionality for the target account
5. Receive the password reset link at the attacker-controlled email
6. Complete the account takeover and gain full access to the victim's account

This attack chain enables complete account takeover including administrative accounts, resulting in potential compromise of the entire application and its data.

Detection Methods for CVE-2025-41077

Indicators of Compromise

• Unusual patterns of user data access requests from a single authenticated session
• Sequential or bulk enumeration of user IDs or identifiers in API requests
• Email address modifications for accounts that don't typically have profile updates
• Password recovery requests immediately following email address changes
• Login events from new locations or devices following a password reset

Detection Strategies

• Monitor API access logs for patterns indicating systematic user enumeration
• Implement alerts for email address modifications on privileged accounts
• Track correlation between email changes and subsequent password recovery requests within short time windows
• Review authentication logs for account access from previously unseen IP addresses or geolocations following password resets

Monitoring Recommendations

• Enable detailed audit logging for all user data access and modification operations
• Configure alerts for bulk or sequential access to user records from a single session
• Implement anomaly detection for password recovery request patterns
• Monitor administrative account activity for signs of unauthorized access

How to Mitigate CVE-2025-41077

Immediate Actions Required

• Restrict access to Viafirma Inbox to trusted network segments until patching is complete
• Implement additional authentication factors for administrative accounts
• Review recent user account modifications for signs of exploitation
• Audit password recovery logs for suspicious patterns of email changes followed by reset requests

Patch Information

Consult the INCIBE Security Notice for the latest patch information and vendor guidance on remediation. Organizations should apply vendor-provided security updates as soon as they become available.

Workarounds

• Implement network-level access controls to limit who can reach the application
• Add web application firewall (WAF) rules to detect and block IDOR exploitation patterns
• Require additional verification (such as administrator approval) for email address changes on privileged accounts
• Consider temporarily disabling self-service password recovery for administrative accounts until the vulnerability is patched

# Example: Restrict access to Viafirma Inbox at the network level
# Add firewall rules to limit access to trusted IP ranges only
iptables -A INPUT -p tcp --dport 443 -s 10.0.0.0/8 -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -j DROP