CVE-2025-59101: Access Manager Auth Bypass Vulnerability

CVE-2025-59101 Overview

CVE-2025-59101 is an authentication bypass vulnerability affecting Access Manager web interfaces. The vulnerability stems from an insecure session management mechanism that relies solely on IP address verification instead of standard session tokens or cookies. Once a source IP address successfully authenticates, all subsequent requests from that IP are treated as authenticated without any additional session validation. This flawed design allows attackers to spoof the IP address of a legitimately authenticated user to gain unauthorized access to the Access Manager web interface.

Critical Impact

Attackers can bypass authentication entirely by spoofing the IP address of an authenticated user, potentially gaining full administrative access to Access Manager interfaces without valid credentials.

Affected Products

• Dormakaba Access Manager (specific versions not disclosed in advisory)
• DKAccess components utilizing IP-based authentication

Discovery Timeline

• 2026-01-26 - CVE CVE-2025-59101 published to NVD
• 2026-01-26 - Last updated in NVD database

Technical Details for CVE-2025-59101

Vulnerability Analysis

This vulnerability is classified under CWE-291 (Reliance on IP Address for Authentication), which represents a fundamental design flaw in the authentication architecture. The Access Manager web interface implements a non-standard authentication scheme that stores only the source IP address upon successful login, rather than generating and managing proper session tokens.

The attack is network-accessible and requires some user interaction in the form of a legitimate user first authenticating to the system. Once an administrator or authorized user logs in from their IP address, an attacker who can spoof or share that IP address can make arbitrary requests to the web interface that will be accepted as authenticated.

This approach fundamentally ignores the well-established security principle that IP addresses are not reliable identifiers for authentication purposes. IP addresses can be spoofed in certain network configurations, shared across multiple users (NAT, proxies, VPNs), and are insufficient to establish a secure session binding between a specific user and the application.

Root Cause

The root cause is the complete absence of cryptographically secure session tokens in the authentication flow. The application was designed to track authenticated sessions by IP address alone, storing no other session-identifying information. This means:

1. No session cookies are generated upon successful login
2. No CSRF tokens are used to validate requests
3. The authentication state is entirely dependent on source IP verification
4. Any request from a previously-authenticated IP is automatically trusted

Attack Vector

The attack vector is network-based and exploits the IP-based authentication mechanism. An attacker can execute this attack through several methods:

1. Direct IP Spoofing: In network environments where IP spoofing is possible (particularly internal networks or misconfigured external networks), an attacker can craft packets with a forged source IP matching an authenticated user.

2. Shared Network Position: If the attacker is behind the same NAT gateway, proxy, or VPN as an authenticated user, they may automatically share the same apparent source IP address.

3. Network Position Manipulation: An attacker with access to network infrastructure could manipulate routing or ARP tables to intercept or impersonate the IP address of an authenticated user.

The attack requires that a legitimate user has recently authenticated to the Access Manager, and that the attacker can either spoof or share that user's source IP address as seen by the application server.

Detection Methods for CVE-2025-59101

Indicators of Compromise

• Multiple distinct user sessions or activities observed from a single IP address within a short timeframe
• Administrative actions performed from IP addresses with no corresponding login events in authentication logs
• Unusual geographic or network-based access patterns from authenticated IP addresses
• Requests from IP addresses that show inconsistent user-agent strings or client fingerprints

Detection Strategies

• Implement correlation rules that match authentication events with subsequent administrative actions to identify sessions without proper login sequences
• Monitor for anomalous patterns where a single IP address appears to be used by multiple distinct users based on behavioral analysis
• Deploy network monitoring to detect potential IP spoofing attempts, particularly looking for packets with source addresses that should not be routable from their ingress point
• Analyze web server logs for requests that are accepted as authenticated but lack corresponding session establishment events

Monitoring Recommendations

• Enable comprehensive logging on Access Manager web interfaces to capture all authentication attempts and administrative actions
• Implement network-level monitoring at ingress points to detect potential IP spoofing attempts
• Configure alerting for administrative actions that occur from IP addresses with no recent successful authentication event
• Consider deploying network behavior analysis tools to identify anomalous traffic patterns indicative of IP spoofing

How to Mitigate CVE-2025-59101

Immediate Actions Required

• Review the Dormakaba Security Advisory for vendor-specific guidance and patches
• Restrict network access to Access Manager web interfaces to trusted internal networks only
• Implement additional network-layer authentication controls such as VPN requirements or certificate-based authentication
• Consider temporarily disabling the affected web interface until a proper fix is applied

Patch Information

Consult the official security advisories for patch availability and update instructions:

• SEC Consult DKAccess Advisory
• SEC Consult Dormakaba Advisory
• Dormakaba Security Advisory

Organizations should contact Dormakaba directly for specific patch information and upgrade paths for their deployed versions.

Workarounds

• Place the Access Manager web interface behind a reverse proxy that implements proper session management and authentication
• Restrict access to the web interface using firewall rules to allow connections only from specific, controlled IP addresses
• Deploy network segmentation to isolate the Access Manager from potentially hostile network segments
• Implement monitoring to detect and alert on any suspected exploitation attempts while awaiting a permanent fix

# Example firewall configuration to restrict access to trusted IPs only
# Adjust IP addresses and interface names for your environment
iptables -A INPUT -p tcp --dport 443 -s 10.0.1.100 -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -s 10.0.1.101 -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -j DROP