2019 - Page 2 of 3 - Layer Seven Security

Recommended Settings for SAP Logging and Auditing

Layer Seven on July 25, 2019

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.

SAP Security Notes, June 2019

Layer Seven on July 5, 2019

Note 2748699 provides instructions for securing the credentials of the standard user SM_EXTERN_WS in SAP Solution Manager. SM_EXTERN_WS is used by CA Introscope Enterprise Manager (EM) to collect monitoring metrics from mainly non-ABAP components in SAP landscapes. The metrics are collected via the Introscope Push web service. The credentials for SM_EXTERN_WS including the automatically generated password are stored in a file that is referenced with property dpcpush.credentials.file in file <EM_install_dir>/sap/<SolMan_SID>.e2emai.properties. The credentials in the file are insufficiently protected against attackers. However, dialog logon with SM_EXTERN_WS is not possible since the user is a system user type. Also, SM_EXTERN_WS does not have administrative privileges.

Note 2748699 recommends deploying the LM-SERVICE software component and patching the Management Module for Enterprise Manager. Also, it includes instructions for enabling encryption to protect the password file.

Switchable authorization checks were introduced by notes 2524203, 2527346 and 2496977 to supplement checks performed using authorization object S_RFC for critical Remote-enabled Function Modules (RFMs) in components of SAP ERP. This includes RFMs in Accounts Receivable and Payable, Materials Management, and Sales and Distribution.

Webinar Playback: Holistic SAP Cybersecurity with CVA & SolMan

Layer Seven on June 20, 2019

Watch the pla yback 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.

SAP Security Notes, May 2019

Layer Seven on June 7, 2019

Note 1408081 was updated in May in response to the recent 10KBLAZE exploits targeting vulnerabilities in the gateway server. The note includes revised instructions for maintaining access control lists in the gateway security files reg_info and sec_info for different kernel versions. The access control lists should be configured to control external server registrations and program starts. The note recommends restricting registrations and starts to within the same system or SID cluster using the options ‘local’ and ‘internal’. However, the updates do not mention the risk that the security mechanisms applied by the recommended entries could be bypassed by attackers that register as internal servers with the message server. Therefore, it is critical to maintain access control lists for the message server to support the secure configuration of the gateway server.

For additional security against 10KBLAZE exploits, a separate port should be configured for internal message server communications, external monitor commands should be rejected, communications between kernel components should be encrypted, and the bit mask value for the profile parameter gw/reg_no_con_info should be set to a value of 255.

Note 2756453 provides manual instructions and automated corrections for removing a high-risk cross-site scripting vulnerability in S/4HANA.

Note 2784307 deals with another high-risk vulnerability in the REST Interface that could be exploited to escalate privileges in SAP Identity Management.

10KBLAZE: Secure Your Systems with SAP Solution Manager

Layer Seven on May 13, 2019

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.

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

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

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

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

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.

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.

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

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

Layer Seven on May 9, 2019

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

SAP Security Notes, April 2019

Layer Seven on May 7, 2019

Note 2747683 patches a vulnerability in the signature security mechanism of the Adapter Engine in SAP NetWeaver Process Integration (PI). The vulnerability could enable attackers to spoof XML signatures and send arbitrary requests to the server via PI Axis adapter. Such requests will be accepted by the PI Axis adapter even if the payload has been altered, especially when the signed element is the body of the xml document. SAP has corrected the relevant code in PI Axis Adapter. The corrections apply additional checks for signed elements for correctness before signature validation. Customers should apply the relevant support packages and patches referenced by SAP Note 2747683.

Note 2776558 provides corrections for a high-risk insufficient authorization check in SAP Funding Management. The vulnerability could be exploited to escalate privileges and carries a CVSS score of 8.3/10.

Notes 2742758 and 2741201 deal with information disclosure vulnerabilities in in the messaging system and runtime workbench of SAP PI. This could lead to the leakage of sensitive system information that could be exploited to perform further attacks against the platform.

Note 2687663 patches a similar vulnerability in the .NET SDK WebForm Viewer of SAP Crystal Reports. Sensitive database information that could be disclosed by exploiting the vulnerability include user credentials.

Securing Administrative Access in SAP AS Java

Layer Seven on April 25, 2019

The misuse of administrative privileges is a common method used by attackers to compromise applications and propagate attacks to connected systems. The elevated privileges granted to administrative accounts are a prized target for attackers and provide a fast path to accessing or modifying sensitive data, programs and system settings.

User privileges for Java applications are administered through the User Management Engine (UME) in the SAP NetWeaver Application Server for Java (AS Java). The UME is the default user store for AS Java and can be configured to use LDAP directories, AS ABAP, or the system database of AS Java as the data source for user-related data.

UME permissions granted to users can include administrative actions such as Manage_All, Manage_Roles, Manage_Users, Manage_User_Passwords, and other privileged functions. Administrative actions are bundled into roles and granted to users organized into user groups. Standard user groups include the Administrator group, as well as groups such as SAP_J2EE_ADMIN and SAP_SLD_ADMINISTRATOR. The latter includes users with administrative access to the System Landscape Directory. Standard roles include Super Admin and, for Enterprise Portals running on AS Java, Portal System Admin, Portal User Admin and Portal Content Admin.

Access to administrative roles and rights in AS Java should be granted to required users only, based on the principle of least privilege. Users with administrative privileges in AS Java systems can be detected using the Cybersecurity Extension for SAP Solution Manager. The results are displayed in security reports and dashboards. Alerts are also triggered by the extension for new users granted privileged roles and actions for possible privilege escalations. The extension also detects users with administrative rights in ABAP and HANA platforms, as well as SAP-compatible databases including IBM, Microsoft, Oracle and Sybase.

SAP Security Notes, March 2019

Layer Seven on April 7, 2019

Note 2764283 addresses an XML External Entity vulnerability in SAP HANA extended application services (XS), advanced. HANA XS does not sufficiently validate an XML document accepted from an authenticated developer with privileges to the SAP space. Successful exploitation of the vulnerability could lead to the leading of arbitrary files in SAP servers or denial of service through resource exhaustion. Note that exploits targeting the vulnerability require either administrative or developer privileges to the SAP space of the XS advanced service. SAP recommends updating to XS advanced runtime version 1.0.102 or later.

Note 2689925 deals with a Cross-Site Scripting (XSS) Vulnerability in the SAML 1.1 SSO Demo App in the SAP NetWeaver Application Server Java. The app does not does sufficiently encode user-controlled inputs. This could lead to unauthorized changes to web content and the theft of user credentials. The vulnerability impacts versions 7.10 – 7.50 of the software component J2EE-APPS. SAP recommends upgrading the component to the relevant patch level for each version specified in Note 2689925.

Note 2524203 introduces a switchable authorization check to secure access to the function module FKK_DOCUMENT_ READ used to read documents in Accounts Receivable and Payable.

Notes 2662687, 2727689, 2754235, 2746946, 2652102 and 2250863 patch insufficient or missing authorization checks in areas such as SAP Enterprise Financial Services, NetWeaver Application Server ABAP, S/4HANA, Convergent Invoicing and the Payment Engine.

Code Vulnerability Management with SAP Solution Manager

Layer Seven on March 10, 2019

Custom Code Management (CCM) in SAP Solution Manager can enable you to take control of custom developments by providing transparency into custom objects in your SAP systems and analyzing the usage of custom code. It can also provide insights into security vulnerabilities in custom objects and packages.

CCM provides an overview of the custom developments in systems and identifies unused or redundant code based on usage statistics from Usage and Procedure Logging (UPL). Decommissioning entire programs or specific lines of code within programs if they are unused or redundant can minimize the attack surface and ensure that time and effort is not wasted managing code-level vulnerabilities in custom developments that are not serving a business need.

Decommissioning in CCM is complemented by tools such as the SAP Clone Finder which identifies custom code that is cloned from SAP standard and supports reverting back to standard code, wherever possible.

CCM displays the results of code checks performed using the ABAP Test Cockpit (ATC). This includes findings from SAP Code Vulnerability Analysis (CVA). CVA performs static application security testing for custom ABAP developments. The tool is used by SAP to scan and secure SAP-delivered code. Therefore, it enables SAP customers to enforce equivalent standards for the security of custom code as enforced by SAP for standard code. Note 1921820 provides details of the security checks performed by CVA. The details are also available in the SAP Community Network.

Enabling CCM is a prerequisite for monitoring the results of CVA checks in SAP Solution Manager. However, CCM is only available to Enterprise support customers and therefore is not available for customers on Standard support. Details of usage rights for Solution Manager are available at the SAP Support Portal.

Licensing restrictions prevent all SAP customers from integrating CVA results with Solution Manager to support holistic cybersecurity monitoring that includes managing risks at the system, user, event and code level.

Layer Seven Security’s custom data connector for CVA resolves this issue by integrating CVA findings directly with the Configuration and Change Database (CCDB) in Solution Manager. This avoids the dependency on CCM and Enterprise support. The data is extracted by the connector from each target system to Solution Manager and automatically updated on a daily schedule. The extracted data is integrated with security reports, dashboards and alerts in Solution Manager to support centralized monitoring for cyber risks in SAP systems including vulnerabilities in custom code. The CVA connector is bundled with the Cybersecurity Extension for SAP Solution Manager.

The raw data for CVA results can be viewed in the custom CCDB store ATC_RESULTS. Results include the check ID, object name, package name, developer name, impacted lines, and a description of each finding.

The findings are mapped to service level reports, web-based reports, and security dashboards in Solution Manager.

CVA results are also integrated with security alerts and email/ SMS notifications generated by SAP Solution Manager.