CVE-1999-0936 in BNBSurvey
Summary
by MITRE
BNBSurvey survey.cgi program allows remote attackers to execute commands via shell metacharacters.
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Analysis
by VulDB Data Team • 10/22/2025
The vulnerability identified as CVE-1999-0936 represents a critical command injection flaw within the BNBSurvey survey.cgi web application component. This issue resides in the survey.cgi program that processes user input through web forms, creating an avenue for malicious actors to execute arbitrary system commands on the affected server. The vulnerability stems from insufficient input validation and sanitization mechanisms within the CGI script, which fails to properly escape or filter special shell metacharacters that users might inject into survey form fields. When the application processes these unfiltered inputs, it directly passes them to the underlying operating system shell, enabling attackers to manipulate the execution flow and gain unauthorized control over the system.
The technical exploitation of this vulnerability follows a well-established pattern that aligns with common software security weaknesses documented in CWE-77 and CWE-94 categories. Attackers can leverage shell metacharacters such as semicolons, ampersands, pipes, and backticks to append malicious commands to legitimate survey data submissions. This type of vulnerability falls under the broader classification of injection flaws within the CWE taxonomy, specifically targeting command execution channels rather than traditional database or script injection vectors. The attack surface is particularly dangerous because it allows remote code execution without requiring authentication, making it a severe threat to web server security. This vulnerability operates at the intersection of multiple ATT&CK techniques including T1059.001 for command and script injection, T1068 for exploit for privilege escalation, and T1566 for social engineering through web applications.
The operational impact of CVE-1999-0936 extends far beyond simple data theft or service disruption. Successful exploitation enables attackers to execute arbitrary code with the privileges of the web server process, potentially leading to complete system compromise. An attacker could use this vulnerability to establish persistent backdoors, escalate privileges to root access, perform data exfiltration, or deploy additional malware within the network. The survey.cgi application likely handles sensitive user information, making the compromise of this component particularly dangerous for organizations that rely on online surveys for customer feedback, employee evaluations, or other data collection purposes. The vulnerability affects systems running the BNBSurvey application on Unix-like operating systems where the CGI script executes shell commands, creating a significant risk for web servers that have not been properly secured or patched.
Mitigation strategies for this vulnerability must address both immediate remediation and long-term security hardening measures. The most effective immediate solution involves applying the vendor-supplied patches or upgrading to a newer version of the BNBSurvey application that properly sanitizes user inputs before processing. Organizations should implement input validation and output encoding mechanisms that prevent shell metacharacters from being interpreted as commands. This includes implementing proper parameterized queries, using safe API calls instead of direct shell execution, and employing web application firewalls that can detect and block suspicious command injection patterns. Additionally, system administrators should ensure that web applications run with minimal required privileges, implement proper access controls, and conduct regular security assessments to identify similar vulnerabilities in other components. The vulnerability demonstrates the critical importance of secure coding practices and input validation, particularly when dealing with user-supplied data that may be processed through system-level commands. Organizations should also implement monitoring solutions to detect anomalous command execution patterns that might indicate exploitation attempts, as this vulnerability can remain undetected for extended periods without proper security controls in place.