Layer Seven Security

Securing the Web Dispatcher with SAP Solution Manager

The SAP Web Dispatcher is an application gateway that filters Internet based traffic to SAP systems including HTTP requests. As an entry point for Web-based communications in SAP landscapes, the Web Dispatcher can help to secure remote access to SAP systems by enforcing security standards for external connections and filtering connection requests.

However, the Web Dispatcher can also be the focal point for attackers looking for an externally reachable pathway to SAP systems. Therefore, it is critical to secure the Web Dispatcher against misuse and prevent attackers from compromising SAP landscapes through poorly configured gateways.

The Web Dispatcher should be regularly patched and updated to prevent attackers from exploiting known program-level vulnerabilities. You should monitor composite note 538405 to stay up-to-date with the latest Web Dispatcher versions.  

Default error messages that disclose sensitive information to attackers should be blocked and replaced with custom messages.

The admin port for the Web Dispatcher should not be accessible from external networks. Administration should be restricted to internal hosts. Public monitoring information in the Web admin interface should be blocked.

SSL should be enforced for connections including communications between the Web Dispatcher and back-end systems and metadata exchange with message servers and application servers.

Finally, filtering should be enabled to enforce positive or negative lists for access requests. The Web Dispatcher supports multiple filtering mechanisms including ACL files and authentication handlers.  ACL files can be used if access should be filtered based on client IP address or IP range. Authentication handlers should be used if requests need to be filtered for specific URLs. Both approaches support logging of successful and unsuccessful requests.  Access to the following URLs should be blocked or restricted:

/sap/public/icman/*
/sap/public/ping
/sap/public/icf_info/*
/sap/wdisp/info

The Cybersecurity Extension for SAP monitors the security of the Web Dispatcher using the SAP Solution Manager platform. The SAP-certified addon detects vulnerable Web Dispatcher versions and patch levels, improper error handling that could lead to information disclosure, the use of insecure Web Dispatcher settings, protocols, and filters, and calls to critical URLs captured in Web Dispatcher logs.

Compliance Reporting for the SAP Security Baseline

The SAP Security Baseline is a widely used benchmark for securing SAP applications. The benchmark includes SAP recommendations for system hardening, authentication and authorization, logging and auditing, and other areas. The recommendations draw on SAP security notes, guides and whitepapers.  The SAP Security Baseline was updated by SAP earlier this year and provides an up-to-date framework for safeguarding SAP ABAP, HANA and Java systems against known vulnerabilities and threats. Note 2253549 includes a link to the latest version of the framework.

The Cybersecurity Extension for SAP Solution Manager performs automated gap assessments for SAP systems against the SAP Security Baseline. The extension identifies compliance gaps in SAP systems to highlight configuration, user and other issues that do not meet SAP requirements defined in the baseline. The extension eliminates the need for periodic, manual audits and supports on-demand compliance reporting.

Control gaps are automatically discovered via daily background jobs. The gaps are reported in the Compliance Report application, accessible from the Fiori launchpad for SAP Solution Manager.

The SAP Security Baseline template can be selected from the list of supported frameworks.

There are optional filters to select specific baseline requirements and systems based on environment or priority. Reports can also be filtered to include or exclude requirements based on risk rating and compliance result.  Once the framework and system is selected, users can select Go to view the results.

The overall compliance level for the system is displayed the report header. The results for each requirement of the SAP Security Baseline are displayed in the main body of the report.  

Users can drilldown into each requirement to review the results for specific controls. Control ratings and descriptions are included in the report to support analysis.

Reports can be exported to CSV or PDF. The Report Detail option specifies whether results are exported at the Requirement, Control or Description level.

Users can also save shortcuts for prefiltered reports to the Fiori launchpad.

RECON: Secure Your Systems with SAP Solution Manager

US-CERT issued Alert AA20-195A on Monday for the so-called RECON (Remotely Exploitable Code On NetWeaver) vulnerability in SAP NetWeaver Application Server Java (AS Java). RECON impacts versions 7.3 and higher of AS Java including an estimated 40,000 SAP systems. Based on a BinaryEdge search, 4,000 of the impacted systems are internet-facing. The vulnerability is rated 10/10 using the Common Vulnerability Scoring System and can be exploited remotely by unauthenticated attackers to fully compromise SAP systems.

RECON targets a missing authentication flaw in the LM Configuration Wizard of AS Java to execute malicious code that creates administrative users in compromised systems. Attackers can exploit RECON to compromise not only AS Java systems but also connected systems including SAP ERP, CRM, SCM, and BW.

CISA strongly recommends SAP customers to apply SAP Note 2934135 to mitigate RECON. The note introduces authentication and authorization for the LM Configuration Wizard and therefore secures against RECON attacks. As a workaround, the application tc~lm~ctc~cul~startup_app can be disabled if the note cannot be applied. The LM Configuration Wizard is required by SAP Landscape Management. According to SAP, “This application is used by a few SAP Lifecycle procedures only, such as the initial technical setup. It is not needed for a day-to-day operations. You can temporarily activate or enable this application for executing the SAP lifecycle procedures.” Procedures for disabling the LM Configuration Wizard are detailed in SAP Note 2939665.

The implementation status of Notes 2934135 and 2939665 for impacted systems should be tracked using System Recommendations (SysRec) in SAP Solution Manager. SysRec connects directly to SAP Support to discover relevant notes for SAP applications, databases and components.

Users can create custom tiles in SysRec to track the implementation status of RECON notes in their SAP landscape from the Fiori launchpad.

The Cybersecurity Extension for SAP Solution Manager monitors Java application logs to detect the signature of RECON exploits. This includes enabling and executing the vulnerable application. The Extension also detects the creation of new administrative users and connections by new users or source IP addresses using anomaly detection. RECON alerts can be investigated using the incident response procedures Preventing RECON Attacks and Investigating Suspected RECON Attacks.

Email and SMS notifications are triggered for RECON alerts. The alerts can also be monitored in Solution Manager using the Alert Inbox, System Monitoring, and other applications. They can also be integrated with SIEM solutions for cross-platform monitoring. Custom alarms can be added to the Fiori launchpad to notify users of suspected RECON exploits.

Securing the SAProuter from Remote Attacks

The surge in remote working has led to an increasing reliance on the SAProuter as a means to facilitate secure remote access to SAP applications. As a reverse proxy between external networks and SAP landscapes, the SAProuter enables organizations to apply more granular policies for filtering and securing connections to SAP systems than network firewalls. However, far from improving security, an improperly configured SAProuter can expose organizations to dangerous exploits that could lead to the compromise of SAP servers.

Since the SAProuter is an internet-facing proxy that provides a direct path to SAP systems, it is an accessible and high-value target for attackers. Port scans against exposed IP addresses will reveal SAProuters available on the standard port 3299. Attackers can send information requests to detected SAProuters to enumerate the scheme for internal IP addresses based on the details of connected hosts disclosed in the response. Once the internal IP address scheme is determined, attackers can then scan the internal network by sending connection requests from the SAProuter to connected hosts. The responses can enable attackers to discover open ports for not only SAP services but services such as HTTP, SMTP, FTP, and SSH if the SAProuter supports native connections.

The information can be used to connect to open and vulnerable services in SAP servers by pivoting through the SAProuter. Once connected, attackers can execute targeted exploits against the servers. For example, an unauthenticated SOAP request to the SAP Host Agent on port 1128 can disclose operating system users that can be targeted using brute force and other attacks. Attackers can also route malicious payloads to SAP servers through the SAProuter.

The secure configuration of the SAProuter can prevent or mitigate such attacks. The route permission table defined in the saprouttab file should specify the source hosts permitted to connect to specific services and target hosts. The use of wildcards in route strings should be avoided. Native connections should be blocked using S entries for the saprouttab rather than P entries. KT and KP entries are recommended to enforce SNC for connections. Information disclosure via the SAProuter should be prevented using the option -Z for info requests. Switching to a non-standard port for the SAProuter is advisable. SAProuter binaries should be updated to the latest available version to apply patches for program vulnerabilities. This includes critical vulnerabilities addressed by notes 1820666 and 1663732. Finally, the SAProuter should be installed in a Demilitarized Zone (DMZ) on a host with a hardened operating system. SAP recommends a C2 class compliant operating system.

Logging for the SAProuter should be enabled using option -G. Once enabled, the SAProuter log can be monitored using SAP Solution Manager to alert for suspected attacks against including accepted or rejected information requests, connection requests, port scans, and native connections.

SAP Vulnerability Assessment vs Penetration Testing

Vulnerability assessment and penetration testing both serve important functions for protecting business applications against security threats. The approaches are complementary but should be deployed sequentially. Penetration testing against systems and applications that have not been hardened based on the results of vulnerability assessments is inadvisable since the results are predictable.  The objective of penetration testing is to assess the strength of security defenses, not to exploit ill-equipped and unprepared systems and processes to prove a point.

Therefore, vulnerability assessments should be performed ahead of penetration tests. The results of comprehensive vulnerability scans inform organizations of configuration, program, user and other weaknesses that could be exploited to compromise systems during real or simulated attacks. The recommendations resulting from the assessments enable organizations to remediate security weaknesses using a prioritized approach. It also supports the implementation of counter measures to detect and respond to potential attacks.

Once systems are hardened and defenses are prepared, performing a penetration test is a valuable exercise to test the adequacy of security mechanisms. The lessons learned from the discovery and exploitation of vulnerabilities during penetration tests can be applied to address areas that may have been overlooked or inadequately secured after vulnerability assessments. Penetration testing against hardened systems that are actively monitored for attacks forces pen testers to exercise more complex and difficult attack vectors. It also compels pen testers to deploy evasive techniques to avoid detection. This improves the quality of penetration tests and the reliability of the results, providing a stronger litmus test for system security, threat detection and incident response.

Monitoring Security Alerts with SAP Solution Manager

There are several apps available in SAP Solution Manager for monitoring security alerts for SAP systems. The most longstanding is the Alert Inbox which provides an overview of alerts by process area. Guided procedures for investigating security alerts are executed from the Alert Inbox. Another option is System Monitoring which provides a more user-friendly interface for navigating incidents than the Alert Inbox. System Monitoring includes the Alert Ticker displayed in the right pane of the app for monitoring incidents in real-time.

SAP Solution Manager 7.2 SP07 introduced a third option for monitoring alerts called Monitor Systems. The app is delivered in the new work center Application Operations.

System Monitoring and the Alert Inbox are Web Dynpro applications. Monitor Systems, however, is a SAPUI5 application based on the Fiori framework. Therefore, Monitor Systems delivers exceptional performance with alerts loading and refreshing at much faster rates than both the Alert Inbox and System Monitoring. The performance gains are considerable even for SAP Solution Manager installations running on conventional databases rather than SAP HANA.   

You can access Monitor Systems from the SAP Fiori Launchpad using the roles SAP_STUI_APPOPS_AUTH and SAP_STUI_APPOPS_TCR.

The initial screen summarizes alerts open alerts by systems and components.

Alerts are categorized by the groups below. Security alerts triggered by the Cybersecurity Extension for SAP Solution Manager are categorized in the Configuration and Exception classes.

Results can be filtered or sorted by clicking by system and category.

Systems can also be labeled as favorites for fast selection.

You can view details of open alerts for each system by clicking on the system. Below are alerts for security configuration issues impacting system AS2.

Below are security exceptions detected through real-time monitoring of event logs in the system.

We can drill down into the details of each alert by clicking on Critical Metrics. For example, we can investigate the alert below for the Actions by the Standard SAP* User Alert by reviewing the relevant metric.

The Metric Details reveals that there was an attempted logon with the SAP* user from IP address 10.8.91.2 at 12:51 on 2019-08-14. We can execute a guided procedure that will investigate other actions from the source IP directly in the Security Audit Log.

The results can be shared with security operations teams through email by clicking on the Notify option in the Metric Details.

In another example, we can drill down into the alert for active users logged into the system with SAP_ALL in their user buffer to investigate potential privilege escalation. The profile should not be used in productive systems.

Recommended Settings for SAP Logging and Auditing

The Cybersecurity Extension for SAP Solution Manager monitors SAP event logs to automatically detect and alert for indicators of compromise. The monitoring interval can be customized for each security metric based on risk and sizing. An interval of 60 seconds, for example, can support real-time threat detection. However, real-time detection is only useful when supported by real-time incident response. Organizations that lack rapid response capabilities should opt for collection intervals of 10-15 minutes to balance the need to minimize the mean to detect (MTTD) with the system impact of continuous monitoring.

Log settings also need to be carefully maintained to capture security-relevant events while preventing the accumulation of log data and the consumption of excessive disk or table space. The recommended settings and archiving procedures below for each log area will enable you to maintain comprehensive forensic logs with minimal system impact.

Security Audit Log
Maintain static filters to log all actions by the standard SAP* user, logons and transaction starts by the DDIC user, and Severe and Critical events for all audit classes and users. Also create a static filter to log the non-critical event IDs BU4, CUY, DU9, DUI, and FU1. The filters should be applied to all clients. If you have yet to remove the EarlyWatch client, also create a filter to monitor events for all audit classes and users in client 066.

Periodically export events older than 30 days using transaction SM20. Once the events are successfully exported and backed-up to a file server, trigger the background job RSAUPURG to delete events older than 30 days using transaction SM18.

Read Access Log
Configure or import logging purposes to log access to sensitive fields and tables including user tables. Archive SRAL objects using transaction SARA. RAL archives can exported and stored offline.

Change Documents
Change documents for user changes are triggered automatically. Similar to the Read Access Log, change documents are archived using transaction SARA.

Business Transaction Log
There are no specific settings required for STAD. Since data is retained for only 48 hours, STAD archiving is also not required.

System Log
Similarly, the system log does not require any specific settings or archiving. The system log is a ring buffer. When the log file reaches its maximum size, the system overwrites the oldest data.

HTTP Log
The LOGFORMAT option for HTTP logging should specify a format that includes the URL in log entries. An example is the CLF format. HTTP log files in the /usr/sap/SID/instance/work directory can be exported and archived offline.

Gateway Server
The ACTION option for gateway logging should include the actions SsZMP to capture security events, configuration changes, and monitor commands. Gateway log files are can also be found in the work directory of each instance and archived to an external location.

Java Security Log
The value of the following properties should be set to TRUE to include the client host address, object name and actor in logged events: ume.logon.security_policy.log_client_hostaddress, ume.secaudit.get_object_name, and ume.secaudit.log_actor. Automatic archiving should be activated using the Log Manager. Once activated, the compressed archives can be found in usr\sap\<SID>\JC<Instance number>\j2ee\cluster\<Dispatcher or server>\log\archive.

HANA Audit Log
The target audit trails should be set to CSTABLE and SYSLOGPROTOCOL to log events simultaneously to internal tables and the OS-level system log. Audit policies should be configured to log critical actions including all actions performed by the SYSTEM user, system changes, user changes, role changes, repository changes, and unsuccessful logons.

The contents of the AUDIT_LOG table can be exported using the AUDIT OPERATOR privilege in the HANA Studio. Once exported, navigate to the Auditing tab in the Security section and select the option to truncate the audit trail.

For detailed step-by-step instructions, refer to the section on Log Settings and Maintenance in the user manual for the Cybersecurity Extension for SAP Solution Manager.

Webinar Playback: Holistic SAP Cybersecurity with CVA & SolMan

Watch the playback of this month’s webinar to learn how you can implement holistic cybersecurity for your SAP systems with Code Vulnerability Analyzer and Solution Manager.

CVA performs static code analysis to detect vulnerabilities in custom code. SAP Solution Manager detects vulnerabilities and threats in SAP systems including components such as the gateway server, message server and SAProuter, targeted by the recent 10KBLAZE exploits. 

Together, CVA and Solution Manager provide an integrated platform to secure custom code and SAP systems against cyber threats.

10KBLAZE: Secure Your Systems with SAP Solution Manager

On May 2, the Department of Homeland Security issued an alert for SAP customers in response to the disclosure of new exploits targeting vulnerable SAP components. According to some reports, the so-called 10KBLAZE exploits could impact 90% of SAP installations worldwide. The exploits target misconfigurations in the gateway server and message server installed in most SAP systems including S/4HANA, ERP and CRM. The successful execution of the exploits could enable attackers to exfiltrate or modify data and provoke a denial of service without authentication. In other words, attackers can completely compromise target SAP systems without any user credentials.

The new exploits target known vulnerabilities addressed by notes and advisories released by SAP since 2005.  Note 821875 details measures to secure the message server, including restricting external access, separating internal and external communications, and maintaining secure access control lists. The profile parameter ms/monitor should be set to 0 to prevent external programs such as msmon from administering the message server at the operating system level. Access to transaction SMMS should also be restricted since the setting can be changed dynamically using the Message Server Monitor within the application server. A separate port for internal communication between application servers should be defined using parameter rdisp/msserv_internal. This will prevent external clients from intercepting or rerouting internal message server communications.  The port should not be exposed to clients or intranets. Finally, the parameter ms/acl_info should specify the file containing a restrictive access control list of hosts, domains, IP addresses or subnets for application servers permitted to log on with the message server.

ACLs should also be defined for the gateway server to control access to starting external programs.  This can be performed using the gateway security file sec_info. The correct syntax for the file depends on the kernel level. For kernel 7.20 and higher, the setting USER-HOST=LOCAL is recommended to protect against 10KBLAZE exploits. This will allow connections from the same server instance. The setting USER-HOST=INTERNAL could be vulnerable but is required for SID clusters. For detailed guidance, refer to Note 1408081. The ACLs should be supported by the setting gw/acl_mode to 1. This parameter defines the behavior of the gateway server if sec_info does not exist.

Since some 10KBLAZE exploits are targeted at modifying or redirecting data packets, enabling SNC to authenticate and encrypt client-server communications is recommended.

SAP systems vulnerable to 10KBLAZE exploits can be discovered using SAP Solution Manager. The Cybersecurity Extension for SAP Solution Manager automatically monitors security settings for the message server and gateway server including profile parameter settings, access control lists and users with critical transactions such as SMMS. The extension also monitors message and gateway logs for external monitor commands, successful and unsuccessful program starts, and other events. Alerts are triggered by the extension for suspected exploits.

The example below illustrates how you can discover insecure sec_info entries that could expose systems to 10KBLAZE exploits.

Click on Vulnerability Report in the Fiori Launchpad.

SAP Cybersecurity Extension for Solution Manager 10

Filter by ABAP systems, select the check-box for the target system and click on Display.

SAP Cybersecurity Extension for Solution Manager 09

Filter for vulnerabilities in open status within the area of RFC Security. Click on the check for starting of external programs.

SAP Cybersecurity Extension for Solution Manager 08

Review the details and recommendation. Click on the linked SAP Notes and SAP Help.

SAP Cybersecurity Extension for Solution Manager 07

Click on Additional Information to review the insecure entries in the sec_info ACL.

SAP Cybersecurity Extension for Solution Manager 03

Focus on entries with the setting USER-HOST=internal.

Click on the download icon to export the current settings.

If required, add comments in the Comment section.

SAP Cybersecurity Extension for Solution Manager 04

The finding for the system will be automatically removed from the report once the sec_info entries are updated. However, you can manually change the status using the Change Status option. Note that status changes are tracked in the extension.

SAP Cybersecurity Extension for Solution Manager 05

You can also assign responsibility for remediating the finding to specific groups using the Change Owner option.

SAP Cybersecurity Extension for Solution Manager 06

Webinar: 10KBLAZE – Secure Your SAP Systems with CVA and SolMan

According to a recent report, thousands of SAP installations may be vulnerable to 10KBLAZE exploits targeting SAP applications.

Join SAP and Layer Seven Security to learn how to secure your SAP systems against the exploits with SAP Code Vulnerability Analyzer (CVA) and SAP Solution Manager. CVA performs static code analysis to detect vulnerabilities in custom code. SAP Solution Manager detects vulnerabilities and threats in SAP systems including components such as the gateway server, message server and SAProuter, targeted by 10KBLAZE.

Together, CVA and Solution Manager provide an integrated platform to secure your business-critical SAP systems against 10KBLAZE and other exploits.

Thu, Jun 6, 2019
11:00 AM – 12:00 PM EDT

REGISTER