CVE-2005-2597 in Client Software
Summary
by MITRE
AOL Client Software 9.0 uses insecure permissions for its installation path, which allows local users to execute arbitrary code with SYSTEM privileges by replacing ACSD.exe with a malicious program.
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Analysis
by VulDB Data Team • 07/30/2017
The vulnerability described in CVE-2005-2597 represents a critical privilege escalation flaw in AOL Client Software version 9.0 that stems from improper access control mechanisms during the installation process. This issue manifests when the software installer creates installation directories with overly permissive permissions that allow unprivileged local users to modify critical system components. The specific file targeted is ACSD.exe, which serves as a core component within the AOL client architecture and operates with elevated privileges during execution. The insecure permissions create a path traversal and code replacement attack vector that enables malicious actors to substitute the legitimate executable with a crafted malicious binary, thereby gaining SYSTEM-level access to the compromised system.
From a technical perspective, this vulnerability aligns with CWE-276, which addresses incorrect permissions for critical resources, and demonstrates how inadequate access control implementation can lead to severe privilege escalation outcomes. The flaw operates through a classic race condition and permission misconfiguration pattern where the installation directory lacks proper discretionary access control lists that would normally prevent non-privileged users from modifying executable files. When the vulnerable software executes ACSD.exe, it runs with SYSTEM privileges due to its legitimate role in the AOL client architecture, making any modification to this file a direct path to system compromise. The vulnerability is particularly concerning because it requires no special privileges to exploit and can be executed by any local user, regardless of their administrative status.
The operational impact of this vulnerability extends beyond simple privilege escalation to encompass full system compromise capabilities that align with ATT&CK technique T1068, which covers local privilege escalation through exploitation of software vulnerabilities. Attackers can leverage this flaw to establish persistent backdoors, exfiltrate sensitive data, or deploy additional malware payloads without requiring initial access through network-based attacks. The vulnerability affects systems running AOL Client Software 9.0 and potentially other versions that share similar installation path configurations, creating a widespread attack surface across organizations that have not updated their software. Network administrators should note that this vulnerability can be exploited without network connectivity requirements, making it particularly dangerous in environments where network segmentation is not properly enforced.
Mitigation strategies for this vulnerability should focus on immediate permission hardening of installation directories and the implementation of proper access control mechanisms. System administrators should ensure that installation paths for critical software components are configured with restrictive permissions that prevent modification by non-privileged users. The recommended approach includes setting appropriate discretionary access control lists that grant only necessary permissions to specific user groups and implementing software restriction policies that prevent execution of unauthorized binaries. Additionally, organizations should implement regular software update procedures to ensure that vulnerable versions of AOL Client Software are removed from systems. The vulnerability also highlights the importance of maintaining up-to-date software inventory and conducting regular security assessments to identify and remediate similar permission-based flaws across the enterprise environment. This issue serves as a prime example of why proper software installation practices and access control configurations are essential for maintaining system integrity and preventing unauthorized privilege escalation attacks.