CVE-2025-42996: SAP MDM Server Auth Bypass Vulnerability

CVE-2025-42996 Overview

CVE-2025-42996 affects the SAP Master Data Management (MDM) Server and enables session hijacking against authenticated clients. An attacker can gain control of existing client sessions and invoke certain server functions without re-authenticating. The flaw permits access to or modification of non-sensitive information and can consume enough server resources to degrade performance. The weakness is classified under [CWE-590], indicating improper handling of resources or session state on the server side. SAP addressed the issue in its Security Patch Day release referenced by SAP Note #3610006.

Critical Impact
Attackers with network access can hijack authenticated MDM sessions and execute functions as legitimate users, causing limited confidentiality, integrity, and availability degradation.

Affected Products

SAP Master Data Management (MDM) Server
SAP MDM client session components
Refer to SAP Note #3610006 for the complete list of affected versions

Discovery Timeline

2025-06-10 - CVE-2025-42996 published to NVD
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-42996

Vulnerability Analysis

The vulnerability resides in how the SAP MDM Server manages authenticated client sessions. Attackers who can interact with the MDM Server over the network can take control of an existing client session and invoke certain server functions without providing new credentials. Because the affected functions operate on non-sensitive data, the direct information exposure is limited. The same session control path can also be abused to submit resource-intensive requests, degrading server performance for legitimate users.

The attack requires no privileges and no user interaction, but the attack complexity is high. This suggests specific conditions must be met, such as observing or predicting session state, timing a request against an active session, or reaching an internal MDM interface. The vulnerability falls within the [CWE-590] weakness class, aligning with improper resource management tied to session lifecycle handling.

Root Cause

The root cause is inadequate re-authentication enforcement on privileged server functions once a client session exists. The server trusts session context for operations that should require fresh authentication or additional authorization checks. This is a design-level access control weakness rather than a memory safety issue.

Attack Vector

Exploitation occurs over the network against a reachable SAP MDM Server. The attacker targets an existing authenticated session and issues function calls that the server processes under that session's identity. Repeated calls can also be used as a denial-of-service primitive by exhausting server resources. No verified public exploit or proof-of-concept is available at the time of writing.

No verified exploit code is publicly available. Refer to the SAP Note #3610006 advisory for vendor technical details.

Detection Methods for CVE-2025-42996

Indicators of Compromise

Unexpected function invocations on the SAP MDM Server tied to session identifiers that show anomalous source addresses.
Sudden CPU, memory, or connection spikes on MDM Server hosts without a corresponding change in legitimate user load.
Session IDs reused from multiple client IP addresses within short intervals.

Detection Strategies

Correlate MDM Server audit logs with authentication events to flag function calls that occur without a preceding authentication or re-authentication event.
Monitor for repeated identical or resource-heavy MDM requests originating from the same session, which may indicate abuse for degradation.
Baseline normal MDM client behavior per user and alert on deviations such as new source networks or off-hours activity.

Monitoring Recommendations

Forward SAP MDM Server logs to a centralized SIEM and retain session, authentication, and function-call events.
Track server performance counters and alert on sustained resource exhaustion patterns aligned with MDM traffic.
Review network segmentation and log any direct external access attempts to MDM Server ports.

How to Mitigate CVE-2025-42996

Immediate Actions Required

Apply the fix described in SAP Note #3610006 as part of the SAP Security Patch Day cycle.
Inventory all SAP MDM Server instances and confirm patch level against the note's guidance.
Restrict network access to MDM Server endpoints to trusted management and application networks only.

Patch Information

SAP released the fix through its Security Patch Day process. Administrators should consult SAP Note #3610006 for exact component versions, prerequisites, and installation steps, and review the SAP Security Patch Day Announcement for the corresponding release cycle.

Workarounds

Enforce short session timeouts on the MDM Server to limit the window in which a session can be hijacked.
Require re-authentication for administrative or sensitive MDM functions where configurable.
Place MDM Server behind a reverse proxy or firewall that terminates untrusted connections and enforces client authentication.

bash

# Example: restrict MDM Server access at the host firewall to trusted subnets
iptables -A INPUT -p tcp --dport 20003 -s 10.0.0.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 20003 -j DROP