CVE-2000-1177 in Big Brother Network Monitor
Summary
by MITRE
bb-hist.sh, bb-histlog.sh, bb-hostsvc.sh, bb-rep.sh, bb-replog.sh, and bb-ack.sh in Big Brother (BB) before 1.5d3 allows remote attackers to determine the existence of files and user ID s by specifying the target file in the HISTFILE parameter.
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Analysis
by VulDB Data Team • 10/11/2025
The vulnerability described in CVE-2000-1177 affects the Big Brother monitoring system version 1.5d3 and earlier, specifically targeting several shell scripts including bb-hist.sh, bb-histlog.sh, bb-hostsvc.sh, bb-rep.sh, bb-replog.sh, and bb-ack.sh. These scripts are part of the system's file handling and reporting mechanisms, designed to process various types of monitoring data and generate reports. The flaw resides in how these scripts handle the HISTFILE parameter, which is intended to specify the target file for historical data processing. When attackers supply malicious input through this parameter, the scripts fail to properly validate or sanitize the input before processing, creating a path for information disclosure attacks.
This vulnerability represents a classic case of improper input validation and inadequate access control mechanisms, falling under the CWE-20 category for improper input validation. The security implications extend beyond simple file enumeration, as the scripts are designed to process user IDs and file paths, making them susceptible to attacks that can reveal sensitive system information. The issue stems from the scripts' failure to implement proper access controls or input sanitization, allowing remote attackers to craft malicious requests that can determine whether specific files exist on the system or identify valid user IDs. This information disclosure vulnerability is particularly concerning because it provides attackers with reconnaissance data that can be used to plan more sophisticated attacks, potentially leading to privilege escalation or further system compromise.
The operational impact of this vulnerability is significant for organizations using Big Brother monitoring systems, as it creates a reconnaissance vector that can be exploited by remote attackers without requiring authentication. Attackers can systematically test various file paths and user identifiers, effectively mapping the target system's file structure and user accounts. This type of information gathering aligns with the ATT&CK framework's reconnaissance phase, specifically covering techniques related to enumeration and discovery of system information. The vulnerability affects the confidentiality aspect of the CIA triad, as it allows unauthorized disclosure of system information that should remain protected. Organizations relying on these monitoring scripts may unknowingly expose sensitive data about their system configuration, potentially revealing file locations, user account structures, or other operational details that could be leveraged in subsequent attacks.
The mitigation strategy for this vulnerability involves multiple layers of defense. First, organizations should immediately upgrade to Big Brother version 1.5d3 or later, which contains the necessary patches to address the input validation issues. System administrators should also implement proper input sanitization mechanisms within the affected scripts, ensuring that all parameters are validated against expected formats and ranges before processing. Network-level protections such as firewalls and access control lists can help limit exposure by restricting access to these scripts from untrusted networks. Additionally, implementing proper logging and monitoring of script execution can help detect potential exploitation attempts. The vulnerability demonstrates the critical importance of input validation in security-critical applications and serves as a reminder that even seemingly benign file handling operations can become security risks when proper validation mechanisms are absent. Organizations should also consider implementing principle of least privilege access controls for these monitoring scripts, ensuring that they operate with minimal required permissions to reduce potential impact if exploited.