CVE-2007-0368 in mbse-bbs
Summary
by MITRE
Stack-based buffer overflow in mbse-bbs 0.70 and earlier allows local users to execute arbitrary code via a long string in the MBSE_ROOT environment variable.
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Analysis
by VulDB Data Team • 08/18/2024
The vulnerability identified as CVE-2007-0368 represents a critical stack-based buffer overflow flaw affecting mbse-bbs version 0.70 and earlier implementations. This issue resides within the handling of environment variables, specifically the MBSE_ROOT variable, which serves as a critical configuration parameter for the mbse-bbs system. The vulnerability arises from insufficient input validation and bounds checking when processing user-supplied data through environment variables, creating an exploitable condition that can be leveraged by local attackers to gain elevated privileges and execute arbitrary code within the system context.
The technical mechanism behind this vulnerability stems from improper memory management practices within the mbse-bbs application code. When the system processes the MBSE_ROOT environment variable, it fails to implement adequate bounds checking mechanisms to prevent buffer overflows. The flaw occurs because the application allocates a fixed-size buffer on the stack to store the environment variable value, but does not validate the length of the input data before copying it into this restricted memory space. This allows an attacker to provide a sufficiently long string that exceeds the allocated buffer capacity, causing adjacent memory locations to be overwritten with attacker-controlled data.
From an operational perspective, this vulnerability presents a significant risk to systems running affected versions of mbse-bbs as it enables local privilege escalation attacks. Since the vulnerability requires local system access to exploit, it primarily affects environments where users have shell access to the system but do not possess administrative privileges. However, the impact remains severe because successful exploitation can result in full system compromise, allowing attackers to execute arbitrary code with the privileges of the mbse-bbs process. This can lead to unauthorized data access, system modification, or complete system takeover depending on the privileges associated with the vulnerable service.
The vulnerability aligns with CWE-121, which describes stack-based buffer overflow conditions that occur when a program writes data beyond the boundaries of a fixed-length stack buffer. This classification indicates the fundamental nature of the flaw as a memory safety issue that can be exploited through improper input handling. From an attack framework perspective, this vulnerability maps to multiple ATT&CK techniques including privilege escalation through local execution and code injection methods. The attack vector requires a local user to set the malicious environment variable, making it a low-impact but high-consequence vulnerability that can be particularly dangerous in multi-user environments where privilege separation is critical.
Mitigation strategies for this vulnerability center on immediate software updates and patches provided by the mbse-bbs developers. Organizations should prioritize upgrading to versions that address this specific buffer overflow condition through proper bounds checking and input validation. Additionally, system administrators should implement environment variable restrictions and monitoring to prevent unauthorized modification of critical configuration parameters. Memory protection mechanisms such as stack canaries, address space layout randomization, and non-executable stack protections can provide additional defense-in-depth measures. Regular security assessments and input validation reviews should be conducted to identify similar vulnerabilities in other applications that may be susceptible to stack-based buffer overflow attacks through environment variable handling.