CVE-2001-1162 in Samba
Summary
by MITRE
Directory traversal vulnerability in the %m macro in the smb.conf configuration file in Samba before 2.2.0a allows remote attackers to overwrite certain files via a .. in a NETBIOS name, which is used as the name for a .log file.
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Analysis
by VulDB Data Team • 01/20/2025
The vulnerability described in CVE-2001-1162 represents a critical directory traversal flaw within the Samba file sharing implementation that affected versions prior to 2.2.0a. This weakness specifically manifests in how Samba processes the %m macro within the smb.conf configuration file, which is designed to represent the NetBIOS machine name in various logging contexts. The flaw enables malicious actors to exploit the way Samba handles NETBIOS names containing directory traversal sequences, allowing them to manipulate file paths and potentially overwrite critical system files. The vulnerability stems from insufficient input validation and sanitization of user-supplied NetBIOS names that are directly incorporated into file system operations without proper path resolution checks.
The technical exploitation of this vulnerability occurs when a remote attacker crafts a malicious NETBIOS name containing .. sequences that are then processed by the %m macro in the smb.conf file. When Samba creates log files using these names, the .. sequences can traverse up directory structures and overwrite files in unintended locations. This occurs because the system fails to properly sanitize the NetBIOS name before using it to construct file paths for log file creation. The vulnerability specifically targets the logging mechanism where the %m macro is expanded, creating a path traversal condition that allows arbitrary file system access. This flaw operates at the intersection of configuration file processing and file system operations, making it particularly dangerous as it can be exploited through network-based attacks without requiring local system access.
The operational impact of this vulnerability is severe and multifaceted, as it can lead to complete system compromise through unauthorized file modification and potential privilege escalation. Attackers can leverage this weakness to overwrite critical system files, modify log files to cover their tracks, or inject malicious content into the system's logging infrastructure. The vulnerability affects the integrity and availability of the Samba service, potentially leading to denial of service conditions or complete system takeover. From a security perspective, this flaw undermines the principle of least privilege and can be exploited to gain persistent access to networked systems. The vulnerability also has implications for audit and compliance requirements, as malicious actors can manipulate log files to hide their activities, making detection and forensic analysis significantly more challenging.
The mitigation strategies for CVE-2001-1162 primarily involve upgrading to Samba version 2.2.0a or later, which contains the necessary patches to address the directory traversal vulnerability. Organizations should also implement network segmentation and access controls to limit exposure of Samba services to untrusted networks. Configuration hardening measures include disabling unnecessary services, implementing proper input validation for NetBIOS names, and restricting file system permissions for log directories. Additionally, monitoring for suspicious NETBIOS name patterns and implementing intrusion detection systems can help identify exploitation attempts. This vulnerability aligns with CWE-22 Directory Traversal and follows ATT&CK techniques related to privilege escalation and persistence through file system manipulation. System administrators should conduct thorough vulnerability assessments to ensure all Samba installations are properly updated and that appropriate security controls are in place to prevent similar issues in the future.