CVE-2003-1289 in FreeBSD
Summary
by MITRE
The iBCS2 system call translator for statfs in NetBSD 1.5 through 1.5.3 and FreeBSD 4 up to 4.8-RELEASE-p2 and 5 up to 5.1-RELEASE-p1 allows local users to read portions of kernel memory (memory disclosure) via a large length parameter, which copies additional kernel memory into userland memory.
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Analysis
by VulDB Data Team • 09/06/2019
The vulnerability described in CVE-2003-1289 represents a critical memory disclosure flaw within the iBCS2 system call translator implementation in operating systems based on NetBSD and FreeBSD. This issue affects versions ranging from NetBSD 1.5 through 1.5.3 and FreeBSD 4 up to 4.8-RELEASE-p2 and 5 up to 5.1-RELEASE-p1, where the system call translator fails to properly validate input parameters during statfs system call processing. The flaw resides in the iBCS2 compatibility layer which translates system calls from the iBCS2 (Intel Binary Compatibility Support) environment to native system calls, creating a potential attack vector through improper memory handling.
The technical implementation of this vulnerability stems from insufficient bounds checking in the statfs system call handler when processing large length parameters. When a local user submits a malformed statfs request with an excessive length parameter, the system call translator fails to validate the parameter size before proceeding with memory copying operations. This oversight allows the system to copy kernel memory contents beyond the intended buffer boundaries into userland memory space. The vulnerability specifically manifests in the iBCS2 compatibility layer where the statfs system call is translated, bypassing normal kernel memory protection mechanisms that would typically prevent such unauthorized access to kernel space data.
The operational impact of this vulnerability is significant as it provides local attackers with the ability to read portions of kernel memory, potentially exposing sensitive information such as kernel addresses, credential data, or other confidential system information. This memory disclosure can serve as a stepping stone for more sophisticated attacks, including privilege escalation attempts or exploitation of other vulnerabilities that might require knowledge of kernel memory layout. The vulnerability is particularly concerning because it operates within the system call translation layer, making it difficult to detect through normal security monitoring and potentially allowing attackers to gather intelligence about the target system's internal state without triggering typical intrusion detection systems.
This vulnerability maps to CWE-200 (Information Exposure) and CWE-125 (Out-of-bounds Read) within the Common Weakness Enumeration framework, representing a classic case of improper input validation leading to information disclosure. From an ATT&CK perspective, this vulnerability aligns with T1005 (Data from Local System) and T1059 (Command and Scripting Interpreter) techniques, as it enables attackers to extract system information and potentially leverage this data for further exploitation. The attack surface is limited to local users with access to the affected systems, but the impact extends beyond simple information disclosure to potentially enable more advanced attack vectors. Mitigation strategies include applying vendor-provided security patches that fix the bounds checking implementation in the iBCS2 system call translator, disabling the iBCS2 compatibility layer if not required, and implementing proper input validation mechanisms to prevent buffer overflow conditions in system call handlers. Additionally, system administrators should consider implementing monitoring for unusual statfs system call patterns and ensure that only necessary compatibility layers are enabled on production systems.