CVE-2019-10197 in Samba
Summary
by MITRE
A flaw was found in samba versions 4.9.x up to 4.9.13, samba 4.10.x up to 4.10.8 and samba 4.11.x up to 4.11.0rc3, when certain parameters were set in the samba configuration file. An unauthenticated attacker could use this flaw to escape the shared directory and access the contents of directories outside the share.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 05/18/2025
This vulnerability represents a critical directory traversal flaw in the samba file sharing service that affects multiple versions within the 4.9.x, 4.10.x, and 4.11.x release lines. The flaw manifests when specific configuration parameters are improperly set, creating a security boundary failure that allows unauthorized access to system resources beyond the intended shared directories. The vulnerability is categorized under CWE-22 as Improper Limitation of a Pathname to a Restricted Directory, which directly relates to the samba service's failure to properly sanitize path references during file access operations. This weakness enables attackers to exploit the service's configuration to navigate outside designated share boundaries and access arbitrary files on the underlying filesystem.
The technical implementation of this vulnerability exploits samba's handling of path resolution when processing file requests from clients. When certain parameters are configured in the smb.conf file, the service fails to properly validate or canonicalize directory paths, allowing attackers to craft requests that traverse directory structures using techniques such as directory traversal sequences. This misconfiguration creates a path traversal condition where relative path references can escape the intended share boundaries and access parent directories. The flaw operates at the filesystem access level, bypassing normal samba share permissions and access controls that should normally restrict user access to specific directory trees. This vulnerability directly maps to ATT&CK technique T1078.002 for Valid Accounts and T1566.001 for Phishing, as attackers can leverage this flaw to gain unauthorized access to sensitive files without requiring authentication or valid credentials.
The operational impact of this vulnerability extends beyond simple unauthorized file access, as it can potentially expose sensitive system information, configuration files, and user data that should remain isolated within designated share boundaries. Attackers could access system configuration files, log files, and other sensitive data that might contain authentication credentials, system information, or other valuable intelligence. The vulnerability affects organizations using samba services for file sharing, potentially compromising entire network file systems and creating lateral movement opportunities for attackers. Organizations with samba servers configured with vulnerable parameters face significant risk of data exposure, particularly in environments where samba serves as a primary file sharing mechanism for network resources. The impact is particularly severe in enterprise environments where samba is used for shared document repositories, user home directories, or other critical file storage services.
Mitigation strategies for this vulnerability require immediate patching of affected samba versions to the latest stable releases, as well as careful review of samba configuration files to ensure proper parameter settings that prevent path traversal. System administrators should implement configuration hardening measures that explicitly restrict directory traversal capabilities within samba shares, disable unnecessary features, and enforce strict path validation for all file access operations. Organizations should conduct comprehensive vulnerability assessments to identify all samba installations and verify that configuration parameters are properly set to prevent this class of vulnerability. The remediation process should include implementing network segmentation, access controls, and monitoring to detect potential exploitation attempts. Additionally, regular security audits should be performed to ensure that samba configurations remain secure and that no new configurations introduce similar path traversal vulnerabilities, as this type of flaw can reappear through misconfigurations or incomplete patching processes that leave systems vulnerable to similar attacks.