CVE-2007-5254 in VBA32
Summary
by MITRE
VirusBlokAda Vba32 AntiVirus 3.12.2 uses weak permissions (Everyone:Write) for its installation directory, which allows local users to gain privileges by replacing application programs, as demonstrated by replacing vba32ldr.exe.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 04/23/2018
CVE-2007-5254 represents a critical privilege escalation vulnerability within VirusBlokAda Vba32 AntiVirus version 3.12.2 that stems from improper access control mechanisms during software installation. This vulnerability falls under the category of weak permissions and inadequate access control as classified by CWE-276, where the antivirus software fails to properly restrict write access to its installation directory. The flaw specifically manifests through the assignment of overly permissive permissions to the Everyone group, granting write access that should be restricted to authorized administrators only. This misconfiguration creates a persistent security weakness that local attackers can exploit to escalate their privileges within the system.
The technical exploitation of this vulnerability occurs through a straightforward but effective method of replacing legitimate executable files with malicious counterparts. Attackers can leverage the write permissions to substitute the vba32ldr.exe file, which serves as a critical component in the antivirus software's operation. This replacement allows the attacker to execute arbitrary code with the privileges of the antivirus service or the user who installed the software, effectively bypassing the intended security protections that the antivirus is designed to provide. The vulnerability demonstrates a fundamental flaw in the software installation process where proper access control lists are not implemented to prevent unauthorized modifications to critical system components.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it fundamentally undermines the security posture of systems running the affected antivirus software. When local users can replace core antivirus executables, they gain the ability to modify the security monitoring capabilities of the system, potentially allowing them to bypass security controls, hide malicious activities, or establish persistent backdoors. This vulnerability creates a scenario where the very security tool designed to protect the system becomes a vector for compromise, which represents a severe deviation from the intended security model. The attack surface is particularly concerning because it requires no specialized knowledge or external tools beyond basic file manipulation capabilities that any local user possesses.
Mitigation strategies for CVE-2007-5254 should focus on immediate permission remediation and long-term architectural improvements to prevent similar issues in antivirus software deployment. System administrators should immediately review and correct the permissions on the VirusBlokAda installation directory, ensuring that only authorized users and groups have write access. This aligns with the principle of least privilege as outlined in cybersecurity best practices and represents a fundamental requirement for maintaining system integrity. Additionally, the antivirus vendor should implement proper access control mechanisms during installation, including mandatory permission restrictions and integrity checks that prevent unauthorized modifications to critical components. The vulnerability also highlights the importance of secure software development practices and the need for proper access control implementation as specified in various security standards and frameworks that address software security and access control mechanisms.