CVE-2000-0986 in Oracle
Summary
by MITRE
Buffer overflow in Oracle 8.1.5 applications such as names, namesctl, onrsd, osslogin, tnslsnr, tnsping, trcasst, and trcroute possibly allow local users to gain privileges via a long ORACLE_HOME environmental variable.
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Analysis
by VulDB Data Team • 05/28/2018
The vulnerability described in CVE-2000-0986 represents a critical buffer overflow condition affecting Oracle 8.1.5 database applications and associated utilities. This flaw specifically targets several key Oracle components including names, namesctl, onrsd, osslogin, tnslsnr, tnsping, trcasst, and trcroute. The vulnerability arises from insufficient input validation when processing the ORACLE_HOME environmental variable, which is a fundamental configuration parameter used by Oracle applications to locate their installation directories and configuration files. When a local user provides an excessively long ORACLE_HOME value, the applications fail to properly bounds-check the input before copying it into fixed-size memory buffers, creating exploitable conditions that can be leveraged for privilege escalation.
The technical implementation of this vulnerability aligns with CWE-121, which describes buffer overflow conditions where insufficient bounds checking allows attackers to overwrite adjacent memory locations. The flaw specifically manifests in the handling of environmental variables within Oracle's application frameworks, where the ORACLE_HOME parameter is directly processed without adequate length validation. This creates a scenario where memory corruption can occur during application initialization or execution, potentially allowing attackers to overwrite critical program structures, return addresses, or other memory segments that control program flow. The vulnerability is particularly concerning because it affects multiple Oracle utilities that are commonly executed with elevated privileges during database administration tasks.
The operational impact of this vulnerability extends beyond simple privilege escalation to encompass potential system compromise and unauthorized access to sensitive database information. Local users who can manipulate the ORACLE_HOME environment variable gain the ability to execute arbitrary code with the privileges of the affected Oracle processes, which typically run with elevated system permissions. This could result in unauthorized database access, data exfiltration, modification of database contents, or even complete system compromise depending on the privilege level of the Oracle service accounts. The vulnerability is particularly dangerous in enterprise environments where Oracle databases are extensively used and where local access might be obtained through various attack vectors including compromised user accounts or insider threats.
Mitigation strategies for this vulnerability should encompass both immediate patching and operational security measures. Oracle released patches for this vulnerability in their subsequent database releases, making it imperative for organizations to apply the appropriate security updates. System administrators should implement strict environment variable controls, particularly limiting the length and content of ORACLE_HOME values that can be set by unprivileged users. The principle of least privilege should be enforced by ensuring Oracle applications run with minimal necessary permissions and by implementing proper access controls on Oracle installation directories. Additionally, monitoring and logging should be enhanced to detect unusual environment variable modifications or execution patterns that might indicate exploitation attempts. Organizations should also consider implementing application whitelisting controls and regular security audits of Oracle installations to prevent unauthorized modifications to critical configuration parameters. This vulnerability demonstrates the importance of secure coding practices and input validation in enterprise software systems, particularly those handling sensitive data and operating with elevated privileges.