Source: cve@mitre.org
Sun SunOS 4.1 through 4.1.3 allows local attackers to gain root access via insecure permissions on files and directories such as crash.
SunOS 4.1 through 4.1.3 systems are vulnerable to a local privilege escalation attack. This vulnerability allows attackers to gain root access by exploiting insecure file permissions, specifically targeting files and directories like crash. Successful exploitation grants complete control over the compromised system, leading to data breaches and system compromise.
Step 1: Identify Vulnerable System: The attacker identifies a SunOS 4.1 through 4.1.3 system.
Step 2: Locate Insecure Files: The attacker identifies files and directories with insecure permissions, such as crash or its related configuration files, that are writable by the attacker's user account.
Step 3: Craft Malicious Payload: The attacker creates a malicious payload, such as a modified version of crash or a malicious configuration file, designed to execute arbitrary code with root privileges.
Step 4: Overwrite Target File: The attacker overwrites the vulnerable file or directory with the malicious payload.
Step 5: Trigger Execution: The attacker triggers the execution of the malicious code, often by waiting for the system to use the compromised file or directory (e.g., a system crash that invokes crash).
Step 6: Gain Root Access: The malicious code executes with root privileges, granting the attacker complete control over the system.
The vulnerability stems from insecure file permissions on critical system files and directories, such as crash. These files and directories are often writable by non-root users, allowing attackers to overwrite them with malicious code. The crash utility, designed for debugging, is often run with elevated privileges. By replacing the legitimate crash utility or its configuration files with a malicious version, an attacker can execute arbitrary code with root privileges. The root cause is a failure to properly restrict access to sensitive system files and directories, leading to a privilege escalation scenario. This lack of proper access control allows for the overwrite of critical system components with attacker-controlled code, resulting in complete system compromise. The vulnerability is exacerbated by the reliance on the crash utility, which inherently operates with elevated privileges, making it a prime target for exploitation.
Due to the age of this vulnerability, it is unlikely to be directly associated with modern APT groups. However, the techniques employed (local privilege escalation via insecure file permissions) are fundamental and could be used by any attacker. This CVE is not listed on the CISA KEV catalog.
Monitor file system access logs for unauthorized modifications to system files and directories, especially those related to debugging tools like crash.
Analyze system logs for suspicious activity, such as unexpected process executions or privilege escalations.
Implement file integrity monitoring to detect changes to critical system files.
Use a vulnerability scanner to identify systems running vulnerable versions of SunOS.
Review file permissions on critical system files and directories, ensuring they are appropriately restricted.
Upgrade to a supported operating system version. This is the most effective remediation, but may not be possible for legacy systems.
Review and correct file permissions on all system files and directories, ensuring that only authorized users and processes have write access. Specifically, restrict write access to files and directories like crash and its configuration files.
Implement a robust file integrity monitoring solution to detect unauthorized modifications to system files.
Regularly audit system configurations to identify and address any insecure settings.
Apply the principle of least privilege, granting users only the minimum necessary permissions to perform their tasks.
Isolate legacy systems from the network or segment them to reduce the attack surface.