CVE-2000-0751 in NetBSD
Summary
by MITRE
mopd (Maintenance Operations Protocol loader daemon) does not properly cleanse user-injected format strings, which allows remote attackers to execute arbitrary commands.
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Analysis
by VulDB Data Team • 01/10/2025
The mopd daemon represents a critical security vulnerability in network maintenance operations protocols where improper input validation creates a dangerous format string vulnerability. This flaw exists within the maintenance operations protocol loader daemon that processes user-supplied data without adequate sanitization mechanisms. The daemon's failure to properly cleanse format strings introduces a serious risk where malicious actors can inject specially crafted payloads that exploit the underlying printf-style formatting functions. When the daemon processes these unvalidated inputs, it inadvertently executes arbitrary commands with the privileges of the running process, typically operating at elevated system levels. This vulnerability directly impacts the integrity and confidentiality of network maintenance operations by allowing unauthorized command execution.
The technical implementation of this vulnerability stems from the daemon's improper handling of user input within format string operations. When user data is passed directly to formatting functions without proper validation or sanitization, attackers can manipulate the format specifiers to control program execution flow. This type of vulnerability maps directly to common weakness enumerations including cwe-134 which specifically addresses format string vulnerabilities in software applications. The attack vector involves sending maliciously crafted input through the maintenance operations protocol interface, where the daemon processes these inputs and executes commands based on the injected format specifiers. The vulnerability is particularly dangerous because it allows remote code execution without requiring authentication, making it an attractive target for attackers seeking to compromise network infrastructure.
The operational impact of this vulnerability extends beyond simple command execution to encompass complete system compromise and network infiltration. Attackers can leverage this weakness to gain unauthorized access to network maintenance systems, potentially escalating privileges and accessing sensitive operational data. The daemon's role in maintenance operations makes it a prime target for attackers seeking to disrupt network services or establish persistent access points. This vulnerability also affects the overall security posture of organizations relying on maintenance operations protocols, as it provides a path for attackers to move laterally within network environments. The remote execution capability means attackers can exploit this vulnerability from outside the network perimeter, making it particularly dangerous for organizations without proper network segmentation.
Mitigation strategies for this vulnerability require immediate implementation of proper input validation and sanitization measures within the mopd daemon. Organizations should implement strict format string validation that prevents user input from containing format specifiers, ensuring all user-supplied data is properly escaped or filtered before processing. The daemon should be updated to use safer string formatting functions that do not allow format string injection, such as using snprintf instead of sprintf with user-controlled inputs. Network segmentation and access controls should be implemented to limit exposure of the maintenance operations protocol to only authorized systems and users. Additionally, regular security assessments and code reviews should be conducted to identify similar vulnerabilities in other network maintenance applications. Organizations should also implement monitoring and logging mechanisms to detect suspicious activities related to maintenance operations protocol usage, providing visibility into potential exploitation attempts and supporting incident response efforts. This vulnerability demonstrates the critical importance of proper input validation in security-critical system components and aligns with attack techniques documented in the attack pattern taxonomy related to command injection and format string exploitation.