CVE-2000-0666 in Linux
Summary
by MITRE
rpc.statd in the nfs-utils package in various Linux distributions does not properly cleanse untrusted format strings, which allows remote attackers to gain root privileges.
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Analysis
by VulDB Data Team • 12/09/2024
The vulnerability identified as CVE-2000-0666 represents a critical format string flaw in the rpc.statd daemon component of the nfs-utils package across multiple Linux distributions. This daemon operates as part of the Network File System (NFS) infrastructure and is responsible for managing NFS client notifications and server status updates. The flaw specifically manifests in how the daemon processes incoming network requests containing untrusted format string arguments, creating an avenue for privilege escalation attacks.
The technical exploitation of this vulnerability stems from improper input validation within the rpc.statd service implementation. When the daemon receives network messages containing format specifiers such as %s, %d, or %x in untrusted input fields, it fails to properly sanitize these inputs before processing them through functions like printf or sprintf. This inadequate sanitization allows attackers to inject malicious format specifiers that can cause the daemon to read arbitrary memory locations or execute arbitrary code with the privileges of the running process. Since rpc.statd typically operates with elevated privileges to manage NFS services, successful exploitation directly results in root privilege escalation.
The operational impact of this vulnerability extends beyond simple privilege escalation to encompass complete system compromise. Attackers can leverage this flaw to execute arbitrary commands with root access, potentially leading to unauthorized data access, system modification, or complete system takeover. The vulnerability affects numerous Linux distributions including Red Hat Enterprise Linux, Debian, and various other Unix-like systems that utilize the standard nfs-utils package. Network-based attacks can be initiated from any remote system that can reach the affected NFS services, making this vulnerability particularly dangerous in networked environments where NFS services are exposed to untrusted networks.
Mitigation strategies for CVE-2000-0666 require immediate patching of the nfs-utils package to ensure proper format string sanitization. System administrators should apply security updates from their respective distribution vendors and verify that rpc.statd properly validates all incoming network inputs. Network segmentation and firewall rules should be implemented to restrict access to NFS services only to trusted hosts, reducing the attack surface. Additionally, monitoring network traffic for suspicious patterns related to NFS service communications can help detect potential exploitation attempts. This vulnerability aligns with CWE-134 which specifically addresses format string vulnerabilities, and represents a classic example of how improper input validation can lead to privilege escalation in network services. From an ATT&CK framework perspective, this vulnerability maps to privilege escalation techniques and can be leveraged as part of broader attack chains targeting system integrity and access control mechanisms.
The widespread nature of this vulnerability across multiple Linux distributions highlights the importance of proper input validation in network services and demonstrates how fundamental security flaws in system components can have cascading effects throughout entire infrastructure ecosystems. Organizations must maintain comprehensive patch management processes and conduct regular security assessments to identify and remediate similar vulnerabilities in their network services and system components.