Source: cve@mitre.org
rpc.lockd in Red Hat Linux 6.1 and 6.2 allows remote attackers to cause a denial of service via a malformed request.
Remote attackers can cause a denial-of-service (DoS) condition on Red Hat Linux 6.1 and 6.2 systems by sending a malformed request to the rpc.lockd service. This vulnerability allows attackers to disrupt critical network file locking functionality, potentially leading to data corruption or system unavailability.
Step 1: Target Identification: The attacker identifies systems running Red Hat Linux 6.1 or 6.2 and confirms the presence of the rpc.lockd service.
Step 2: Malformed Request Generation: The attacker crafts a specially designed, malformed request. The exact nature of the malformation is not specified in the CVE, but it likely exploits a parsing or processing vulnerability.
Step 3: Request Delivery: The attacker sends the malformed request to the rpc.lockd service, typically over the network (e.g., TCP or UDP).
Step 4: Vulnerability Trigger: The rpc.lockd service receives and attempts to process the malformed request.
Step 5: Denial of Service: Due to the vulnerability, the rpc.lockd service crashes, hangs, or exhausts resources, resulting in a DoS condition. This prevents legitimate clients from accessing network file locking services.
The vulnerability lies within the rpc.lockd service, specifically in its handling of network requests. The malformed request likely exploits a flaw in how rpc.lockd parses or processes incoming data. This could involve a lack of proper input validation, leading to an integer overflow, buffer overflow, or other memory corruption issues. The specific function or logic flaw is not explicitly stated in the CVE description, but the result is a crash or resource exhaustion within the rpc.lockd process, resulting in a DoS.
Due to the age of the vulnerability, it is unlikely to be actively targeted by sophisticated APTs. However, it could be exploited by less skilled attackers or incorporated into automated scanning tools. This vulnerability is not listed in the CISA KEV.
Monitor network traffic for unusual or malformed RPC requests to port 4045 (or other ports used by rpc.lockd).
Analyze system logs for rpc.lockd crashes, errors, or unexpected behavior.
Implement intrusion detection systems (IDS) with signatures that identify malformed RPC requests.
Monitor CPU and memory usage of the rpc.lockd process for spikes or unusual patterns.
Upgrade to a supported version of Red Hat Linux that includes a patched version of rpc.lockd.
Apply security patches provided by Red Hat.
Restrict network access to the rpc.lockd service using firewalls or access control lists (ACLs).
Disable the rpc.lockd service if it is not required.
Implement a host-based intrusion detection system (HIDS) to monitor for suspicious activity.