Subject: SAP-ABAP (Security and Crime Prevention in SAP)
Input sanitization is a cornerstone of secure SAP ABAP development, especially in the context of preventing cybercrimes like SQL injection, cross-site scripting (XSS), and data manipulation attacks. While basic input validation and simple filtering are necessary, advanced input sanitization techniques provide stronger, more reliable protection against evolving threats targeting SAP systems.
This article explores sophisticated methods and best practices for input sanitization in ABAP to safeguard SAP applications and data.
Sanitize inputs based on where they are used:
Example: Escaping HTML special characters
DATA lv_raw_input TYPE string VALUE '<script>alert("XSS")</script>'.
DATA lv_sanitized TYPE string.
lv_sanitized = cl_abap_html_conv=>escape_html( lv_raw_input ).
WRITE lv_sanitized.
SAP provides utility classes and function modules designed to sanitize and validate inputs:
CL_ABAP_REGEX for pattern matching and validation.CL_ABAP_HTML_CONV for HTML encoding/decoding.SCP_REPLACE_SPECIAL_CHAR to clean input strings.Avoid dynamic SQL construction with string concatenation. Instead, use Open SQL with host variables to prevent SQL injection.
SELECT * FROM mara INTO TABLE @DATA(lt_mara)
WHERE matnr = @lv_input.
Never embed raw inputs directly into SQL strings.
Normalize inputs to a canonical form before validation, e.g.:
This prevents attackers from obfuscating malicious input.
Combine whitelisting with regular expressions to allow only specific input formats, e.g., email, phone numbers, or numeric IDs.
Example: Email validation regex
DATA(lo_regex) = cl_abap_regex=>create( pattern = '^[\w.-]+@[\w.-]+\.\w{2,4}$' ).
DATA(lo_matcher) = lo_regex->create_matcher( text = lv_email ).
IF lo_matcher->find( ) = abap_true.
WRITE: 'Valid Email'.
ELSE.
WRITE: 'Invalid Email'.
ENDIF.
For inputs like URLs or JSON, parse and sanitize each component individually. For instance, extract query parameters and validate them separately before processing.
Implement logging for inputs that fail sanitization or validation checks. Use SAP Application Logging (transaction SLG1) to monitor and alert suspicious activity.
Advanced input sanitization is vital to protect SAP systems from increasingly sophisticated cybercrimes. By adopting context-aware encoding, leveraging SAP’s standard APIs, enforcing strict input normalization, and combining whitelisting with pattern matching, ABAP developers can build resilient applications.
Proactively sanitizing inputs not only prevents attacks but also ensures data integrity, regulatory compliance, and overall system stability in SAP landscapes.