Oracle9i Application Server OWA_UTIL procedures expose sensitive information

Overview

Oracle9i Application Server (iAS) provides a Procedural Language/Structured Query Language (PL/SQL) application (package) called OWA_UTIL that provides web access to a number of stored procedures. These procedures could be used by an attacker to view the source code of PL/SQL applications, obtain credentials and access to other database servers, and run SQL queries on accessible database servers.

Description

David Litchfield of NGSSoftware has released a paper titled Hackproofing Oracle Application Server that describes a number of security issues in Oracle’s PL/SQL system. This document addresses a problem in which a number of procedures in the OWA_UTIL PL/SQL application disclose sensitive information.

Quoting from Hackproofing:

PL/SQL is Oracle’s Procedural Language extension to Structured Query Language. PL/SQL packages [applications] are essentially stored procedures in the database. The package exposes procedures that can be called directly, but also has functions that are called internally from within another package. The PL/SQL module for Apache extends the functionality of a web server, enabling the web server to execute these stored PL/SQL packages in the database. The best way to imagine the PL/SQL module is like a gateway into an Oracle database server over the Web using stored procedures.
The OWA_UTIL PL/SQL application exposes a number of procedures to the web via the Apache PL/SQL module. By default, anonymous web access is permitted to some of these procedures.

OWA_UTIL.signaturereturns a message containing version information about the PL/SQL module. An attacker could use this procedure to verify access to OWA_UTIL.

OWA_UTIL.showsource returns the source code of the specified PL/SQL application. According to Oracle9i AS v1.0.2.2 documentation, web access to OWA_UTIL.cellsprint is prevented by default.

OWA_UTIL.cellsprint allows an attacker to run arbitrary SQL queries. Litchfield notes that queries could be made to the sys.link$ table, which could provide credentials and access to other Oracle database servers. According to Oracle9i AS v1.0.2.2 documentation, web access to OWA_UTIL.cellsprint is prevented by default.

OWA_UTIL.listprint allows an attacker to run arbitrary SQL queries, but only returns specified columns.

OWA_UTIL.show_query_columns returns column names of a database table. This procedure could be used to obtain column names for use with OWA_UTILS.listprint.

The PL/SQL module provides a configuration parameter called exclusion_list. Procedures (as well as applications and schemas) specified in exclusion_list cannot be directly executed over the web. As noted above, Oracle9i AS v1.0.2.2 documentation states that web access to OWA_UTIL.showsource and OWA_UTIL.cellsprint is prevented by default.

The vulnerable PL/SQL module may also be used by Oracle9i Database and Oracle8i Database.

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Impact

An unauthenticated, remote attacker could use procedures provided by OWA_UTIL to view the source code of PL/SQL applications, obtain access credentials for other database servers, access other database servers, and perform SQL queries on accessible database servers.

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Solution

** Block or Restrict Access**
Unauthenticated PUBLIC access to PL/SQL procedures and applications can be restricted using the exclusion_list parameter in the PL/SQL gateway configuration file, /Apache/modplsql/cfg/wdbsvr.app. This solution is described in Oracle Security Alert #28. For more information, read the section titled Protecting the PL/SQL Procedures Granted to PUBLIC in the Oracle iAS documentation under Using the PL/SQL Gateway.

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Disable Vulnerable Service

Disable the PL/SQL service (modplsql or mod_plsql in Apache).

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Vendor Information

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Oracle __ Affected

Notified: March 03, 2002 Updated: March 05, 2002

Status

Affected

Vendor Statement

Oracle has released Oracle Security Alert #28.

Vendor Information

The vendor has not provided us with any further information regarding this vulnerability.

Addendum

The CERT/CC has no additional comments at this time.

If you have feedback, comments, or additional information about this vulnerability, please send us [email](<mailto:[email protected]?Subject=VU%23307835 Feedback>).

CVSS Metrics

Group	Score	Vector
Base
Temporal
Environmental

References

• <http://www.nextgenss.com/papers/hpoas.pdf&gt;
• <http://otn.oracle.com/deploy/security/pdf/ias_modplsql_alert.pdf&gt;
• <http://www.securityfocus.com/bid/4294&gt;
• <http://www.iss.net/security_center/static/8451.php&gt;

Acknowledgements

The CERT Coordination Center thanks David Litchfield of NGSSoftware for information used in this document.

This document was written by Art Manion.

Other Information

CVE IDs:	CVE-2002-0560
CERT Advisory:	CA-2002-08 Severity Metric: