Source: cve@mitre.org
Buffer overflow in Solaris kcms_configure command allows local users to gain root access.
Solaris systems are vulnerable to a critical buffer overflow in the kcms_configure command, allowing local attackers to escalate privileges to root. Successful exploitation grants complete control over the compromised system, potentially leading to data breaches and system compromise.
Step 1: Input Preparation: The attacker crafts a malicious input string. This input is designed to be larger than the buffer allocated within the kcms_configure command. The input also contains shellcode, typically a sequence of machine instructions that, when executed, will spawn a root shell.
Step 2: Input Delivery: The attacker executes the kcms_configure command, providing the crafted input as an argument. This is typically done from a local user account on the Solaris system.
Step 3: Buffer Overflow: The kcms_configure command attempts to copy the attacker's input into a fixed-size buffer. Due to the input's size exceeding the buffer's capacity, a buffer overflow occurs. Data is written beyond the buffer's boundaries, overwriting adjacent memory regions.
Step 4: Return Address Overwrite: The attacker's carefully crafted input overwrites the return address stored on the stack. The return address is modified to point to the attacker's injected shellcode.
Step 5: Shellcode Execution: When the kcms_configure command attempts to return, it jumps to the address specified by the overwritten return address. This causes the shellcode to be executed with the privileges of the kcms_configure process, which is typically root.
Step 6: Privilege Escalation: The shellcode executes, typically spawning a root shell, giving the attacker complete control over the compromised system.
The vulnerability lies within the kcms_configure command, specifically in how it handles user-supplied input. The command fails to properly validate the size of the input data before copying it into a fixed-size buffer. This leads to a buffer overflow when a malicious input exceeding the buffer's capacity is provided. The overflow overwrites adjacent memory locations, including critical data such as the return address on the stack. By carefully crafting the malicious input, an attacker can overwrite the return address with the address of a shellcode, effectively redirecting program execution to the attacker's code. This shellcode, typically injected into the overflowed buffer, then executes with root privileges, granting the attacker complete control of the system.
While no specific APT groups are exclusively known to target this specific CVE, any threat actor seeking to gain root access on Solaris systems could leverage this vulnerability. This vulnerability is not listed on the CISA KEV catalog due to its age and the limited number of vulnerable systems still in operation.
Monitor system logs for suspicious activity related to the kcms_configure command, such as unusual command-line arguments or frequent execution attempts.
Analyze process execution history for instances of kcms_configure being run with unusually long or malformed arguments.
Implement file integrity monitoring to detect changes to the kcms_configure binary or related system files.
Network monitoring for unusual traffic patterns originating from the compromised host after exploitation (e.g., attempts to connect to external command and control servers).
Examine core dumps or memory snapshots for evidence of buffer overflows and shellcode injection.
Apply the vendor-provided patch or security update. This is the most effective remediation.
If patching is not immediately feasible, restrict access to the kcms_configure command. This can be achieved by limiting the users who can execute the command.
Implement robust input validation to prevent buffer overflows. This includes checking the size and format of all user-supplied input.
Employ a least-privilege model, ensuring that users and processes have only the necessary permissions.
Consider using a host-based intrusion detection system (HIDS) to monitor for malicious activity.
Regularly audit system configurations and security settings to identify and address potential vulnerabilities.