CVE-2002-2023 in Shingo Beep2
Summary
by MITRE
The get_parameter_from_freqency_source function in beep2 1.0, 1.1 and 1.2, when installed setuid root, allows local users to read arbitrary files via unknown attack vectors.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 04/19/2019
The vulnerability identified as CVE-2002-2023 affects the beep2 utility version 1.0 through 1.2, specifically when installed with setuid root permissions. This critical flaw resides within the get_parameter_from_frequency_source function which processes frequency parameters from external sources. The issue represents a classic privilege escalation vulnerability where a local attacker can exploit the setuid root binary to gain elevated privileges and access sensitive system resources. The vulnerability stems from inadequate input validation and parameter handling within the frequency source processing mechanism, creating potential attack vectors that allow unauthorized file access.
The technical implementation of this vulnerability exploits the setuid bit functionality where the beep2 utility executes with root privileges despite being invoked by regular users. When the get_parameter_from_frequency_source function processes external inputs without proper sanitization, it creates opportunities for attackers to manipulate the parameter parsing logic. This flaw enables attackers to construct malicious inputs that bypass normal file access restrictions and potentially read arbitrary files on the system. The attack vectors remain unspecified in the original description, suggesting either buffer overflow conditions, format string vulnerabilities, or improper file path handling within the frequency source parameter processing.
From an operational impact perspective, this vulnerability poses significant security risks to systems running affected versions of beep2. Local users can leverage this weakness to read sensitive files that would normally be restricted to root access, potentially exposing system configuration files, password databases, or other critical information. The vulnerability essentially undermines the principle of least privilege by allowing non-privileged users to escalate their privileges and access protected system resources. The presence of setuid root binaries makes this particularly dangerous as it provides direct access to system-level resources without requiring additional exploitation techniques.
The vulnerability aligns with CWE-20 (Improper Input Validation) and CWE-264 (Permissions, Privileges, and Access Controls) categories, representing a combination of input handling flaws and privilege escalation mechanisms. From an ATT&CK framework perspective, this vulnerability maps to T1068 (Local Privilege Escalation) and T1566 (Phishing) as attackers may use social engineering to convince users to execute malicious commands that trigger the vulnerable function. The lack of specific attack vectors in the description suggests this may involve complex exploitation techniques requiring precise input manipulation to achieve the file reading functionality.
Mitigation strategies should focus on immediate patching of affected beep2 versions or complete removal of the vulnerable setuid binary from systems. System administrators should verify that no instances of beep2 version 1.0 through 1.2 exist with setuid root permissions. Additionally, implementing proper input validation and parameter sanitization within the frequency source processing function would prevent exploitation attempts. Regular security audits should ensure that setuid binaries are properly reviewed and that unnecessary privilege escalation mechanisms are eliminated from system components. Network segmentation and monitoring for unusual file access patterns can help detect potential exploitation attempts. Organizations should also consider implementing privilege separation techniques and avoiding setuid binaries for utilities that can be easily exploited through parameter manipulation attacks.