Layer Seven Security

Security Advisory for Critical SAP ICMAD Vulnerabilities

Layer Seven on February 15, 2022

International threat intelligence agencies including the U.S Cybersecurity & Infrastructure Security Agency (CISA) and the Computer Emergency Response Team for the EU (CERT-EU) issued security advisories last week for critical vulnerabilities in the SAP Internet Communication Manager (ICM). The ICM supports inbound and outbound communication with SAP systems using the HTTP(S) protocol. It is a standard component of the NetWeaver Application Server ABAP and Java and the SAP Web Dispatcher.

The advisories relate to CVE-2022-22536, CVE-2022-22532 and CVE-2022-22533, labelled ICMAD (Internet Communication Manager Advanced Desync). The most critical is CVE-2022-22536: a memory corruption vulnerability that can be exploited through a single HTTP request to fully compromise SAP systems, remotely and without authentication. This impacts AS ABAP and the Web Dispatcher when they are accessed through an HTTP gateway. For AS ABAP, the gateway could be the Web Dispatcher. The vulnerability does not impact direct access to SAP application servers. CVE-2022-22532 impacts AS Java only. This vulnerability has a lower CVSS than CVE-2022-22536 due to a higher attack complexity, but ranks high in terms of impact to Confidentiality, Integrity, and Availability. CVE-2022-22533 is for a lower priority denial of service vulnerability in AS Java triggered by requests that exhaust Memory Pipes (MPI) used for communicating between the ICM and work processes in application servers.

There is evidence of active scanning for ICMAD. SAP systems exposed to the Internet are especially vulnerable. External-facing Web Dispatchers are equally vulnerable. Consequently, it is critical to apply the relevant security notes to patch SAP systems against ICMAD.

Note 3123396 patches AS ABAP and the Web Dispatcher for CVE-2022-22536. SAP Kernels and Web Dispatchers should be updated to the minimum patch levels detailed in the note. The workaround detailed in note 3137885 can be applied as a stop-gap measure if the patches cannot be implemented at short notice. For access through the Web Dispatcher, refer to 3137885 to ensure that Web Dispatcher installations meet the minimum patch level. To apply the workaround, the profile parameter wdisp/additional_conn_close should be set to TRUE. For more details, refer to note 3138881.

Note 3123427 patches AS Java for CVE-2022-22532 and CVE-2022-22533. The workaround recommended in the note can be applied using the parameter setting icm/handle_http_pipeline_requests=FALSE if support for HTTP pipeline requests is not required.

The Cybersecurity Extension for SAP discovers vulnerable ABAP, Java and Web Dispatcher installations that have not been successfully patched for ICMAD. It also identifies missing or incorrectly applied workarounds if the corrections in notes 3123396 and 3123427 have not been applied. The SAP-certified solution performs over 1800 checks for known vulnerabilities in SAP applications and components and supporting databases and operating systems.

Securing SAP Systems from Log4J Exploits

Layer Seven on December 17, 2021

The Cybersecurity and Infrastructure Security Agency (CISA) has designated the recent Log4J vulnerability as one of the most serious in decades and urged organizations to immediately address the vulnerability in applications.  

Log4j is an open-source logging framework maintained by the Apache Foundation. The framework includes the API Java Naming and Directory Interface (JNDI). Strings passed through JNDI can force Log4J to query remote LDAP or other servers, download serialized Java code from the malicious servers, and execute the code during deserialization if message lookup substitution is enabled. This can lead to the complete compromise of impacted applications and systems. The remote code execution vulnerability impacts all versions of Log4J2 up to and including 2.14.1 in Java 8 or higher.

Message lookup substitution is disabled by default in Log4j 2.15.0. It has been removed altogether from 2.16.0. Therefore, customers should upgrade to the latest version of Log4J. The vulnerability is addressed by CVE-2021-44228 which has a base CVSS score of 10.0.

CISA has added CVE-2021-44228 to the Known Exploited Vulnerabilities Catalog due to evidence of widespread active exploitation of the vulnerability by multiple threat actors. This includes nation state groups originating from China, Russia, Iran, and North Korea. According to some reports, threat actors are exploiting the vulnerability to deploy ransomware payloads or to gain access to target networks. The access is then brokered to other threat actors.

Log4J is included in multiple SAP applications including SAP HANA XSA. The central note 3131047 includes available patches for impacted solutions. Refer to the SAP’s official response for details of all impacted products. Note 3129883 includes manual procedures for a workaround that will disable the loading of external code in Log4J using the J2EE Config Tool.

The Cybersecurity Extension for SAP identifies vulnerable SAP systems that have not been patched for the Log4J vulnerability. It also detects and alerts for suspected exploits targeted against SAP Java and Web Dispatcher installations based on exploit signatures. This includes known obfuscations and bypass methods.

CISA Issues Directive for Actively Exploited SAP Vulnerabilities

Layer Seven on November 23, 2021

The US Cybersecurity and Infrastructure Security Agency (CISA) issued Binding Operational Directive 22-01 on November 3 to compel government departments and agencies to remediate specific vulnerabilities with known exploits. According to CISA, the vulnerabilities pose a significant risk to information systems. This includes several vulnerabilities for SAP applications that must be remediated by May 3, 2022. Agencies have 60 days to review and update their vulnerability management policies in accordance with the Directive.

The Directive addresses weaknesses with the Common Vulnerability Scoring System (CVSS) used for rating Common Vulnerabilities and Exposures (CVE) in the National Vulnerability Database (NVD). CVSS does not take into account active exploitations for vulnerabilities. Most critical CVEs are highly complex and have no known exploits. The Directive shifts the focus to CVEs with active threats. These vulnerabilities are prioritized for remediation and are classified in the CISA catalog for Known Exploited Vulnerabilities (KEV).

The catalog includes six CVEs for SAP applications.

CVE-2010-5326 is for the invoker servlet implemented in the InvokerServletclass within the Web Container of the J2EE for SAP NetWeaver Application Java (AS Java). The invoker servlet is vulnerable to authentication bypass, enabling remote attackers to execute arbitrary code via HTTP or HTTPS requests. The servlet is disabled by default in higher versions of AS Java. Refer to SAP note 1445998 for disabling the relevant property of the servlet_jsp service on server nodes. SAP also recommends scanning or reviewing application code to identify the usage of servlets with the prefix “/servlet/”. Applications should use local servlets only that are defined in web.xml files. Auth constraints in web xml files are recommended to restrict the invoking of the servlet to users with an administrative role.  

CVE-2016-3976 relates to a directory traversal vulnerability in AS Java that could be exploited to read arbitrary files from servers remotely and without authentication using CrashFileDownloadServlet. Note 2234971 provides a patch for the LM-CORE to address the CVE.

CVE-2020-6287 is for the RECON vulnerability in the LM Configuration Wizard of AS Java. Attackers can exploit a missing authentication check in the CTCWebService to perform administrative functions such as creating privileged users. Note 2934135 includes a patch to validate user input for log paths and block arbitrary log file locations and extensions.

CVE-2018-2380 relates to a directory traversal vulnerability in SAP CRM.  There is a publicly-available exploit for the CVE that could be deployed to perform remote code execution through log file injection. Note 2547431 includes a patch to validate user input for log paths and block arbitrary log file locations and extensions.

CVE-2016-9563 is for a Denial of Service vulnerability in a BPM service within AS Java. This CVE also has a publicly-available exploit. Note 2296909 disables the resolving of external entities during XML parsing to address the CVE.

CVE-2020-6207​ relates to a missing authentication check for the SAP EEM servlet in SAP Solution Manager. A module for the Metasploit penetration framework automates the exploitation of the CVE. This could be exploited to execute OS commands on connected SMDAgents via the /EemAdminService/EemAdmin page for User Experience Monitoring. Note 2890213 includes a patch for the impacted LM-SERVICE software component and instructions for a temporary workaround involving enabling authentication for the EemAdmin service in the Java stack of Solution Manager.

The Cybersecurity Extension for SAP is an SAP-certified solution that automates the discovery of applications vulnerable to the CVEs for SAP applications in the KEV catalog. It also monitors SAP logs to detect the signature of exploits targeting the CVEs and provides mechanisms to investigate and respond to the exploits.  

Security Monitoring with Focused Insights for SAP Solution Manager

Layer Seven on October 28, 2021

Focused Insights is an advanced dashboard framework that was previously available only for MaxAttention customers as part of the MaxAttention Next Generation Add-On (MANGO) but is now available for all SAP customers. Focused Insights can now be installed in SAP Solution Manager 7.2 without any additional SAP licensing or user and usage restrictions.

Focused Insights for SAP Solution Manager provides ready-to-use templates for monitoring a range of KPIs for SAP landscapes. Customers can select from over 800 best practice KPIs for multiple use cases. The framework is organized in three levels: Operational, Governance and Strategic. Security metrics are monitored primarily in the Tactical Dashboard, accessible from the Focused Insights Launchpad.

The Tactical Dashboard can monitor several instances. Instances are groups of systems geared for different users or groups. Instances are setup and maintained using the TAC Configuration option. This includes relevant systems, scenarios and thresholds for KPIs.

The current version of the dashboard supports eleven scenarios such as Availability, Performance, Operations, and Security. Each scenario is rated green, red or yellow based on the thresholds and options maintained in the configuration.

The Dashboard is refreshed automatically every 10 minutes but the frequency can be changed from 5 to 30 minutes and maintained separately for each instance.

The security scenario supports monitoring of security metrics for ABAP, HANA, and Java systems and the SAP Web Dispatcher.  It reports the number of very high (hot news) and high rated security notes that are unapplied in each system, users with critical privileges including the SAP_ALL profile, systems that are open for direct changes, insecure client settings, RFC destinations configured with privileged users, and misconfigurations in specific security-relevant profile parameters. Notes information is sourced from System Recommendations in SAP Solution Manager. The results of other security checks are derived from Configuration Validation using target systems supplied by SAP.

Focused Insights 2.0 SP7 and higher supports the integration of custom target systems with the security scenario in the Tactical Dashboard. This can be used to support monitoring for additional security checks beyond the SAP standard delivery.  

Securing the SYSTEM User in SAP HANA

Layer Seven on August 30, 2021

The SYSTEM user is the most powerful database user in SAP HANA with system-wide privileges including permissions to create and maintain other users, perform system changes, stop and start services, and create and drop databases and tables. The user is created during the initial setup of SAP HANA. Once the system is setup, the SYSTEM user should be deactivated and other users should be created for administrative tasks. The user is not required for HANA updates but should be reactivated for system upgrades, installations and migrations. This includes support stack and enhancement pack upgrades.

Since the SYSTEM user is a well-known administrative user with full system privileges, it is often targeted by threat actors. This article outlines measures to secure the user against attacks and detect and alert for actions performed by the user.

1. Reset Initial Password

Initial passwords for the SYSTEM user for both the system database and the first tenant database are set by hardware partners or administrators. The password should be reset immediately after the handover. The reset can be performed using SQL statements or the SAP HANA cockpit by a user with the USER ADMIN or DATABASE ADMIN privilege. Password resets can also be performed by the <sid>adm user from the system database.

2. Deactivate the User

The SYSTEM should not be used for data-to-day activities, especially in production systems. Create alternative dedicated users for each administrative scenario and then deactivate the SYSTEM user. The user can be temporarily reactivated for emergency tasks, when required. Deactivation can be performed using the SQL statement ALTER USER SYSTEM DEACTIVATE USER NOW and reactivation using the statement ALTER USER SYSTEM ACTIVATE USER NOW. The status of the user can be confirmed by reviewing the values in the columns USER_DEACTIVATED, DEACTIVATION_TIME, and LAST_SUCCESSFUL_CONNECT for the SYSTEM user in the USERS system view.

3. Create Audit Policies

Configure audit policies to log for all actions performed by the SYSTEM user and changes to the user such as password changes and user activation/ deactivation. Once activated, the policies will automatically log events to the audit trail. Audit policies can be created using SQL statements or the Auditing tab of the SAP HANA cockpit with the AUDIT ADMIN privilege. Actions should include both successful and unsuccessful events. Events can be written to one of the supported audit trail targets specified in each policy or the default audit trail if none is specified. Maximum retention periods can also be specified for each policy.

4. Monitor the Audit Trail

Monitor HANA audit logs using System Monitoring in SAP Solution Manager. Configure automated alerts and email/ SMS notifications for actions performed by the SYSTEM user or changes to the user. Integrate alerts with SIEM systems for SOC monitoring. Finally, investigate alerts using guided procedures in SAP Solution Manager.

Securing Software Supply Chains for SAP Systems

Layer Seven on June 30, 2021

Software supply chain attacks are advanced cyberattacks that target information systems through third party software. Threat actors compromise systems and data by exploiting software builds or interfaces for trusted software. This enables attackers to introduce malware without detection including backdoors.

The recent software supply chain attack experienced by SolarWinds is widely regarded as one of the most devastating cyber attacks in history.  It impacted as many as 425 of the US Fortune 500, the top ten US telecommunications companies, the top five US accounting firms, all branches of the US Military, the Pentagon, the State Department, the world’s largest cybersecurity firm, as well as thousands of organizations worldwide. The attack cost affected companies an average of $12M.

Download the whitepaper from Layer Seven Security for guidance on securing software supply chains in SAP landscapes. The whitepaper outlines the threat vectors that could be exploited by attackers to compromise third party software that support SAP applications. It provides practical steps for minimizing third party software and external connections in SAP landscapes, avoiding the use of open source components, and monitoring third party software. The steps are aligned to the Cyber Supply Chain Risk Management (C-SCRM) practices recommended by the National Institute of Standards and Technology (NIST).

Webinar Playback: Protecting SAP Systems from Ransomware Attacks

Layer Seven on June 30, 2021

Ransomware is headline news, and recent attacks have demonstrated the devastating impact of attacks that target critical infrastructure. According to the Department of Homeland Security ransomware attacks have increased by 300% over the past year, impacting all industries and sectors. The average downtime from an attack is 21 days, but full recovery takes an average of 287 days. 

Ransomware can impact SAP systems through vulnerable operating systems. However, securing host systems alone does not safeguard SAP systems from ransomware. Attackers can exploit trust relationships between SAP applications and underlying operating systems to execute privileged OS commands that avoid detection. This can include commands that enable threat actors to transfer, install, and execute ransomware tools. 

This webinar will discuss steps you can take to secure your business-critical SAP systems from ransomware. It will provide an integrated strategy for:

• Identifying and prioritizing critical SAP assets and infrastructure;

• Hardening SAP systems to reduce the attack surface;

• Activating and monitoring SAP logs to detect suspected attacks; and 

• Backing up and restoring SAP systems to minimize the downtime from successful attacks.

The webinar will also discuss how to use SAP Solution Manager to support your anti-ransomware program, from identifying and removing vulnerabilities that could be exploited to attack your systems to detecting and alerting for suspected security breaches.

You can view the webinar recording at SAPinsideronline.com.

Protecting SAP Systems from Ransomware

Layer Seven on May 14, 2021

The recent attack at Colonial Pipeline has demonstrated the devastating impact of ransomware on critical infrastructure. According to the Department of Homeland Security, ransomware a­ttacks have increased by 300% over the past year, impacting all industries and sectors. The average downtime from an att­ack is 21 days. Full recovery takes an average of 287 days.

Ransomware can impact SAP systems through vulnerable operating systems. However, securing SAP hosts alone does not safeguard SAP systems from ransomware. Att­ackers can exploit trust relationships between SAP applications and underlying operating systems to execute privileged OS commands that avoid detection. This can include commands that enable threat actors to transfer, install and execute ransomware tools.

The newly released guide Protecting SAP Systems from Ransomware includes actions you can take to secure your business-critical SAP systems from ransomware. It provides an integrated strategy for:

  • Identifying and prioritizing critical SAP assets and infrastructure;
  • Hardening SAP systems to reduce the attack surface;
  • Activating and monitoring SAP logs to detect suspected attacks; and
  • Backing up and restoring SAP systems to minimize the downtime from successful attacks.

The guide also discusses how to use SAP Solution Manager to support your anti-ransomware program, from identifying and removing vulnerabilities that could be exploited to attack your systems to detecting and alerting for suspected security breaches.

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Cybersecurity Extension for SAP Identifies Signatures of Active SAP Cyberattacks

Layer Seven on April 27, 2021

Earlier this month, SAP issued a joint report with a security research firm to highlight active cyber threats targeting SAP applications. According to the report, there is conclusive evidence that attackers are actively targeting and exploiting unsecured SAP applications. The report also reveals that some SAP vulnerabilities are being weaponized in less than 72 hours from the release of SAP patches.  Unprotected cloud installations of SAP are being discovered and compromised in less than 3 hours.

The investigation performed for the report identified over 300 successful exploitations of SAP systems. This included attempts to modify users and configurations and exfiltrate business information. Most of the exploits targeted the six CVEs below. Although the vulnerabilities have been patched by SAP, many organizations have not applied the recommended mitigations to protect SAP systems.

CVE-2010-5326 (SAP Security Note 1445998)
CVE-2018-2380 (SAP Security Note 2547431)
CVE-2016-3976 (SAP Security Note 2234971)
CVE-2016-9563 (SAP Security Note 2296909)
CVE-2020-6287 (SAP Security Note 2934135)
CVE-2020-6207 (SAP Security Note 2890213)

SAP recommends customers to immediately assess vulnerable systems to identify indicators of compromise such as unauthorized privileged users. The assessment should include systems within SAP landscapes that are connected to the vulnerable targets. The related SAP security notes and recommendations should also be applied in impacted systems.

SAP also urges customers to implement appropriate cybersecurity measures to protect SAP applications. The Cybersecurity Extension for SAP is an SAP-certified solution that performs automated vulnerability management, threat detection and incident response to secure SAP systems from cyber threats. This includes exploits that target the CVEs highlighted in the report. The Extension detects misconfigured and unpatched systems. It also detects the signatures of exploits that target the CVEs, triggers alerts and notifications for suspected breaches, and provides guided procedures for investigating incidents. To learn more, contact Layer Seven Security.

Securing Linux Platforms for SAP HANA and S/4HANA

Layer Seven on March 26, 2021

SUSE Linux Enterprise Server (SLES) is the leading operating system for SAP HANA and SAP S/4HANA solutions, supporting 85 percent of HANA deployments worldwide. SLES for SAP Applications is optimized to support high availability and persistent memory and endorsed by SAP.

Securing operating systems is a critical component of SAP system hardening. Vulnerable hosts can provide a pathway to SAP applications, databases and other components, bypassing security mechanisms applied in those layers. This can lead to the compromise of SAP systems including the corruption of critical files and tables. It can also support ransomware attacks that disrupt the availability of SAP services.

The Cybersecurity Extension for SAP performs daily automated scans to identify vulnerabilities in SAP hosts. For SLES, this includes authentication settings, firewall configurations, file and service permissions, root access, missing security patches, vulnerable packages and services, and misconfigured settings for logging and auditing. It also includes the detection of open TCP/ UDP ports that are targeted by attackers, including FTP, RPC, RDP, SSH, and Telnet.

SLES vulnerabilities are mapped to SAP systems, supporting holistic security across code, application, database and operating system layers.

The SAP-Certified extension also monitors SLES logs to identify indicators of compromise in SAP hosts. Alerts and notifications are triggered for security incidents and channeled to SIEM and service desk systems. This includes the following scenarios:

  • Changes to operating system configuration, profile, and kernel parameters
  • Firewall and other network settings
  • File system mounts and unmounts
  • Group, user and password changes
  • Cron jobs
  • Daemon and service changes
  • OS scripts
  • External connections
  • Sudo users
  • Root and sudo commands
  • Failed logon and file access attempts
  • Critical file changes
  • File permission changes
  • OS code injection
  • User locks and unlocks

Audit records from the SLES audit log are displayed in the alert details. The records include the audit event number and auid of the initial user that triggered the event.

The Cybersecurity Extension for SAP includes integrated incident response procedures to support forensic investigations. Users can select the Respond option from an alert to start an investigation and document the findings.