CVE-2023-48826 in Time Slots Booking Calendar
Summary
by MITRE • 12/07/2023
Time Slots Booking Calendar 4.0 is vulnerable to CSV Injection via the unique ID field of the Reservations List.
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Analysis
by VulDB Data Team • 03/01/2026
The Time Slots Booking Calendar plugin version 4.0 contains a critical csv injection vulnerability that affects the reservations list functionality. This vulnerability arises from insufficient input validation and sanitization within the unique ID field processing mechanism. When administrators or users export reservation data to csv format, the system fails to properly escape or sanitize special characters that could be interpreted as csv formula commands by spreadsheet applications. The vulnerability specifically targets the unique ID field which typically contains alphanumeric identifiers that may inadvertently include characters such as equals signs, plus signs, minus signs, or at symbols that spreadsheet applications interpret as formula execution directives.
This csv injection flaw stems from a fundamental lack of proper data sanitization practices during export operations. The plugin's implementation does not employ adequate input filtering or output encoding when preparing data for csv export functionality. The unique ID field serves as the primary attack vector since it often contains sequential numbers or formatted identifiers that can be manipulated to contain malicious csv formula syntax. According to the CWE database, this vulnerability maps to CWE-1236 which describes insufficient input validation in csv export operations and CWE-770 which addresses improper handling of special characters in data export functions. The vulnerability aligns with ATT&CK technique T1059.001 which involves command and scripting interpreter execution through malicious input manipulation.
The operational impact of this vulnerability extends beyond simple data corruption or display issues. An attacker who can manipulate the unique ID field during reservation creation or modification can potentially execute arbitrary commands on systems where the exported csv data is opened in spreadsheet applications. When spreadsheet applications like Microsoft Excel or Google Sheets process the malicious csv file, they may interpret the injected formulas as actual commands, leading to potential code execution or data exfiltration. This creates a significant risk for administrative users who routinely process booking data through csv exports, as they may unknowingly trigger malicious payloads simply by opening exported files. The vulnerability also poses a risk to automated data processing systems that consume csv files, potentially leading to unauthorized command execution in server environments.
Mitigation strategies for this vulnerability require immediate implementation of proper input sanitization and output encoding mechanisms within the plugin's export functionality. The system must implement automatic escaping of special characters in the unique ID field during csv export operations, particularly ensuring that characters such as equals signs, plus signs, minus signs, and at symbols are properly escaped or quoted. Administrators should disable csv export functionality until proper sanitization is implemented, or configure the export system to automatically prefix potentially dangerous values with a single quote character. The plugin developers should also implement comprehensive input validation that rejects or sanitizes any input containing csv formula syntax. Additionally, security awareness training should be provided to users who regularly handle booking data exports, emphasizing the importance of verifying file integrity before opening csv files in spreadsheet applications. Organizations should consider implementing network-level restrictions that prevent automatic execution of formulas in spreadsheet applications and establish proper access controls to limit who can modify reservation data that might be exported to csv format.