CVE-2007-5690 in Zaptel
Summary
by MITRE
** DISPUTED ** Buffer overflow in sethdlc.c in the Asterisk Zaptel 1.4.5.1 might allow local users to gain privileges via a long device name (interface name) in the ifr_name field. NOTE: the vendor disputes this issue, stating that the application requires root access, so privilege boundaries are not crossed.
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Analysis
by VulDB Data Team • 08/08/2024
The vulnerability described in CVE-2007-5690 relates to a buffer overflow condition found in the sethdlc.c component of Asterisk Zaptel version 1.4.5.1. This issue occurs within the handling of device names through the ifr_name field of the interface structure, which is commonly used in network interface configuration operations. The buffer overflow represents a classic security flaw where an attacker can provide input exceeding the allocated buffer space, potentially leading to memory corruption and arbitrary code execution. The vulnerability specifically affects local users who can manipulate the device name parameter, suggesting a local privilege escalation vector rather than a remote attack surface.
The technical implementation of this vulnerability stems from insufficient input validation within the sethdlc.c file where the ifr_name field receives device name data without proper bounds checking. When a device name exceeds the predetermined buffer size, the excess data overflows into adjacent memory locations, potentially overwriting critical program data or execution control structures. This type of vulnerability maps directly to CWE-121, which describes stack-based buffer overflow conditions, and CWE-122, which covers heap-based buffer overflows. The flaw demonstrates poor memory management practices where input length validation is absent or inadequate, allowing attackers to manipulate program flow through controlled memory corruption.
From an operational perspective, the impact of this vulnerability depends heavily on the execution context and privilege model of the affected system. While the vendor disputes the severity by stating that the application requires root access, this assertion does not fully address the potential for privilege escalation within the system. The local user context suggests that an attacker with access to the system could exploit this vulnerability to elevate their privileges, particularly if they can manipulate the device name parameter through legitimate system interfaces. This scenario aligns with ATT&CK technique T1068, which covers local privilege escalation through exploitation of system vulnerabilities. The actual operational risk is heightened when considering that local users may have access to system configuration interfaces or may be able to manipulate network interface parameters through legitimate administrative functions.
The mitigation strategies for this vulnerability should focus on implementing proper input validation and bounds checking within the affected code. Developers should ensure that all input parameters, particularly those used in system interface operations, are validated against maximum allowed lengths before being copied into fixed-size buffers. The implementation should follow secure coding practices such as using safe string functions like strlcpy instead of strcpy, and employing proper buffer size calculations that account for null terminators and other required metadata. Additionally, system administrators should ensure that the Zaptel component is properly patched and updated to versions that address this buffer overflow condition. The vulnerability also underscores the importance of privilege separation and least privilege principles, where even local users should not be able to manipulate system interfaces in ways that could lead to privilege escalation. Regular security audits and code reviews focusing on input validation and memory management practices should be implemented to prevent similar issues in other system components.