CVE-2005-1495 in Oracle10g
Summary
by MITRE
Oracle Database 9i and 10g disables Fine Grained Audit (FGA) after the SYS user executes a SELECT statement on an FGA object, which makes it easier for attackers to escape detection.
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Analysis
by VulDB Data Team • 11/21/2024
Oracle Database versions 9i and 10g contain a critical security flaw that fundamentally undermines the effectiveness of Fine Grained Audit mechanisms through improper privilege handling. This vulnerability stems from the database's design where the SYS user, who possesses the highest level of administrative privileges, triggers an automatic disabling of FGA when executing SELECT operations against objects that have active audit policies. The technical implementation flaw occurs because the database engine does not properly maintain audit policy states when the privileged SYS user performs read operations, creating an unintended security boundary that attackers can exploit to evade monitoring systems.
The operational impact of this vulnerability is severe as it directly compromises the integrity of database audit trails and monitoring capabilities. When an attacker gains access to the SYS account or can escalate privileges to reach the SYS user level, they can execute SELECT statements against any audited object and effectively nullify the audit policies that were previously configured. This behavior creates a window of opportunity where malicious activities can occur without detection, as the database system automatically disables its own monitoring mechanisms. The vulnerability particularly affects environments where database administrators implement FGA as part of their security strategy, since the very mechanism designed to detect suspicious activities becomes ineffective when the most privileged user performs routine operations.
This flaw aligns with CWE-284, which addresses improper access control in software systems, and represents a classic case of privilege escalation abuse that undermines security controls. From an ATT&CK framework perspective, this vulnerability maps to techniques involving privilege escalation and defense evasion, specifically T1078 for valid accounts and T1562.001 for disabling security tools. The vulnerability exists because the database system fails to properly separate the administrative functions of the SYS user from the audit enforcement mechanisms, creating an inherent design weakness that allows the highest privileged user to inadvertently disable security controls they are supposed to be enforcing. Organizations implementing database security controls must recognize that this vulnerability can be exploited by both insider threats and external attackers who gain administrative access, making it a critical concern for database security architecture.
Mitigation strategies for this vulnerability include implementing strict access controls for the SYS user account, regularly auditing SYS user activities, and ensuring that FGA policies are maintained through alternative mechanisms that cannot be easily bypassed. Database administrators should also consider implementing additional monitoring solutions that can detect when audit policies are disabled or when SYS user activities occur, as well as regularly reviewing and validating audit configurations to ensure they remain effective. The recommended approach involves establishing automated alerting systems that trigger when FGA policies are modified or disabled, combined with strict privilege management protocols that limit SYS user access to only essential operations. Organizations should also consider upgrading to newer database versions where this vulnerability has been addressed through improved privilege handling and audit policy enforcement mechanisms.