Subject Area: SAP-ABAP (Security & Cybercrime Prevention)
Path Traversal attacks, also known as directory traversal attacks, are a critical security threat that can affect SAP ABAP systems when file handling is involved. In such attacks, malicious users manipulate file path inputs to access unauthorized files or directories, potentially exposing sensitive data or compromising system integrity.
This article explores what path traversal attacks are, their risks in the SAP ABAP context, and best practices for preventing them to protect SAP environments from security breaches — a key concern in SAP-ABAP-crimes.
A path traversal attack occurs when an attacker exploits insufficient validation of file path inputs to navigate outside the intended directory structure. For example, by using sequences like ../ in file names, an attacker can access files like system configuration files, user data, or SAP source code.
Never trust user input for file paths. Validate inputs against a whitelist of allowed directories or filenames.
CONSTANTS: c_base_path TYPE string VALUE '/usr/sap/app/data/'.
IF strpos( iv_file_path, '..' ) > 0 OR
strpos( iv_file_path, '\' ) > 0.
MESSAGE 'Invalid file path.' TYPE 'E'.
ENDIF.
DATA lv_full_path TYPE string.
lv_full_path = c_base_path && iv_file_path.
Build full file paths by concatenating a trusted base directory with sanitized file names to prevent navigation outside allowed folders.
Filter or reject input containing ../, \, or other path traversal patterns.
Where possible, use SAP-provided function modules or classes that handle path security internally.
Restrict file system permissions to only those necessary for the SAP application user to minimize damage if a traversal attack occurs.
Implement logging of file operations to detect suspicious access patterns.
DATA: lv_file_name TYPE string VALUE 'report.txt',
lv_base_path TYPE string VALUE '/usr/sap/app/data/',
lv_full_path TYPE string.
IF strpos( lv_file_name, '..' ) > 0 OR
strpos( lv_file_name, '\' ) > 0.
MESSAGE 'Invalid file name.' TYPE 'E'.
ENDIF.
lv_full_path = lv_base_path && lv_file_name.
" Proceed with file read using lv_full_path
../../etc/passwd.Path traversal attacks represent a significant security risk in SAP ABAP environments, potentially leading to unauthorized file access and system compromise. Developers must rigorously validate and sanitize all file path inputs, use fixed base directories, and leverage SAP’s secure APIs to prevent these attacks.
By adopting these best practices, SAP teams can safeguard sensitive data and maintain system integrity — effectively preventing SAP-ABAP security crimes related to path traversal vulnerabilities.