CVE-2019-2638, CVE-2019-2633, Oracle Payday Vulnerabilities - AppDefend Protection

Two Oracle E-Business Suite security vulnerabilities (CVE-2019-2638, CVE-2019-2633) fixed in April 2019 Oracle Critical Patch Update (CPU) have been recently publicized. These vulnerabilities allow an attacker to execute arbitrary SQL statements in the Oracle E-Business Suite data that can result in complete compromise of the environment including fraudulent transactions, changing of bank accounts, and circumvention of application security controls. Integrigy’s AppDefend, the application firewall for Oracle E-Business Suite, is the only solution that provides virtual patching for and proactive defense against these vulnerabilities.

These two vulnerabilities are in the Oracle E-Business Suite (EBS) TCF Server, which provides services to the professional Forms interface for a limited set of Forms. TCF Server is implemented and enabled in all versions of Oracle E-Business Suite including 11i, 12.0, 12.1, and 12.2. It can not be disabled without a customization to Oracle EBS.

TCF Server is a servlet running as part of the standard Oracle EBS web application server and communicates using HTTP or HTTPS between the Forms Java client and the web application server. For R12, the servlet is available at the URL /OA_HTML/AppsTCFServer. It uses a proprietary application-level protocol to communicate between the Forms client and server.

The risk is that unlike most Oracle EBS SQL injection vulnerabilities that only allow for fragments of SQL statements to be appended to standard Oracle EBS SQL statements being executed, these security bugs allow execution of complete SQL statements as the Oracle EBS APPS database account. When evaluating the risk of these vulnerabilities in your environment, it is important to differentiate between external access to the Oracle EBS environment through the Internet when modules like iSupplier, iStore, and iRecruitment are being used and internal access from only your internal network. The risk from external access is critical and should be immediately addressed. The internal risk is still high and dependent on the security posture of your internal network. It is important to realize that non-Oracle EBS aware web application firewalls, database security tools, and other network security products will not provide any protection from successful exploitation of these vulnerabilities.

Integrigy AppDefend is the only solution that provides virtual patching for and proactive defense against these TCF Server vulnerabilities as well other Oracle EBS security vulnerabilities. Integrigy recognized the potential issues with TCF Server and even the first release of AppDefend for R12 in 2007 blocked external access to the TCF Server by default.

AppDefend provides multiple layers of protection against TCF Server vulnerabilities as follows -

  1. Blocks all access to TCF Server externally (since 2007).
  2. Enforces Oracle EBS access control for TCF Server allowing only authorized EBS users to access to the TCF Server (since 2018).
  3. Whitelists the functions accessible through TCF Server (since 2018).
  4. Blocks specific vulnerabilities in TCF Server (2018, 2019).
  5. Advanced SQL injection protection optimized specifically for Oracle EBS will detect and block most of the SQL statements used in TCF Server and other 0-day attacks. (since 2007).

If you do not have AppDefend, applying the latest Oracle Critical Patch Update for Oracle EBS will remediate these specific vulnerabilities and for external sites it is critical that the Oracle EBS URL Firewall is implemented as documented in Appendix E of My Oracle Support Note ID 380490.1. However, these solutions will not protect you prior to applying the security patches or against future TCF Server vulnerabilities and other Oracle EBS 0-day attacks.

Please let us know if you have any questions regarding the latest Oracle EBS security vulnerabilities at

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