CVE-2015-1515 in DefenseWall Personal Firewall
Summary
by MITRE
The dwall.sys driver in SoftSphere DefenseWall Personal Firewall 3.24 allows local users to write data to arbitrary memory locations, and consequently gain privileges, via a crafted 0x00222000, 0x00222004, 0x00222008, 0x0022200c, or 0x00222010 IOCTL call.
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Analysis
by VulDB Data Team • 11/30/2024
The vulnerability identified as CVE-2015-1515 resides within the dwall.sys kernel driver component of SoftSphere DefenseWall Personal Firewall version 3.24, representing a critical privilege escalation flaw that fundamentally undermines system security. This issue manifests through improper input validation and memory management within the driver's handling of specific IOCTL (Input/Output Control) commands, creating an exploitable condition that allows local attackers to manipulate kernel memory directly. The affected IOCTL codes 0x00222000, 0x00222004, 0x00222008, 0x0022200c, and 0x00222010 all share a common vulnerability pattern where user-mode applications can craft malicious requests that bypass normal kernel protection mechanisms, effectively enabling arbitrary code execution at kernel level.
The technical exploitation of this vulnerability follows a well-defined pattern that aligns with common kernel-mode exploit techniques and maps directly to CWE-787, which describes "Out-of-bounds Write" conditions in software. The flaw occurs because the kernel driver fails to properly validate input parameters before writing to memory locations, creating a buffer overflow scenario where attacker-controlled data can overwrite critical kernel memory structures. This particular implementation allows for direct memory manipulation through carefully crafted IOCTL requests that specify memory addresses where the driver will write data, effectively creating a primitive for privilege escalation that can be leveraged to execute code with system-level privileges.
From an operational perspective, this vulnerability presents a severe risk to systems running the affected firewall software, as local users who might not normally have elevated privileges can exploit this flaw to gain full system control. The impact extends beyond simple privilege escalation, as successful exploitation can enable attackers to install rootkits, modify system files, disable security features, and establish persistent backdoors. The vulnerability's exploitation requires local access but does not need network connectivity, making it particularly dangerous in environments where local user accounts might be compromised or where users with legitimate access could be coerced into executing malicious code. This aligns with ATT&CK technique T1068, which covers "Local Privilege Escalation" through kernel exploits, and represents a classic example of how driver-level vulnerabilities can be weaponized for system compromise.
The mitigation strategies for this vulnerability must address both immediate remediation and long-term security hardening. The primary solution involves updating to a patched version of SoftSphere DefenseWall Personal Firewall that properly validates IOCTL parameters and implements proper memory bounds checking. Organizations should also consider implementing kernel-mode exploit detection mechanisms and monitoring for suspicious IOCTL activity patterns. System administrators should enforce least privilege principles, disable unnecessary kernel drivers, and conduct regular security assessments of installed software components. Additionally, the vulnerability highlights the importance of kernel driver security auditing and the need for robust input validation across all system components. This case demonstrates how seemingly minor flaws in kernel-mode drivers can create catastrophic security implications, emphasizing the critical need for security-by-design principles in system software development and the importance of maintaining up-to-date security patches across all system components.