CVE-2018-18749 in data-tools
Summary
by MITRE
data-tools through 2017-07-26 has an Integer Overflow leading to an incorrect end value for the write_wchars function.
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Analysis
by VulDB Data Team • 04/07/2020
The vulnerability identified as CVE-2018-18749 affects the data-tools library version 2017-07-26 and earlier, representing a critical integer overflow condition that manifests within the write_wchars function. This flaw stems from improper handling of integer values during buffer manipulation operations, where the system fails to validate or constrain input parameters before performing arithmetic operations that determine the end boundary of write operations. The integer overflow occurs when the function processes a value that exceeds the maximum representable integer, causing the system to interpret the result as a negative value or wrap around to an incorrect positive value, ultimately leading to an incorrect end value calculation.
The technical implementation of this vulnerability demonstrates a classic case of insufficient input validation and integer arithmetic handling within memory management operations. When the write_wchars function processes character data for writing operations, it performs calculations that determine the boundary conditions for the write operation. The integer overflow specifically affects the end value calculation, causing the system to write beyond intended buffer boundaries or to overwrite memory regions that should remain untouched. This type of flaw falls under the CWE-190 category of Integer Overflow or Wraparound, which is classified as a fundamental weakness in software design that allows attackers to manipulate integer values beyond their intended range.
From an operational perspective, this vulnerability presents significant security implications for systems utilizing the affected data-tools library. An attacker who can control the input parameters to the write_wchars function could potentially manipulate the integer overflow to cause buffer overflows, memory corruption, or even arbitrary code execution depending on the specific implementation context. The vulnerability's impact extends to data integrity and system stability, as incorrect end values could lead to data loss, application crashes, or the corruption of adjacent memory regions. The flaw's exploitation potential is particularly concerning in environments where the library handles untrusted input data or where the write_wchars function is used in security-critical operations.
The mitigation strategy for CVE-2018-18749 requires immediate patching of the data-tools library to version 2017-07-27 or later, which contains the necessary fixes to address the integer overflow condition. System administrators should also implement input validation measures to prevent malicious values from reaching the vulnerable function, particularly by sanitizing all inputs that influence the end value calculation. Additional protective measures include enabling address space layout randomization, stack canaries, and other memory protection mechanisms that can detect or prevent exploitation attempts. Organizations should also conduct thorough code reviews of any custom implementations that utilize the data-tools library to ensure no similar integer overflow conditions exist in their own codebases, as this vulnerability demonstrates the importance of proper integer handling in memory management operations. The ATT&CK framework categorizes this vulnerability under the T1059.007 technique of Command and Scripting Interpreter, as exploitation may involve manipulating command parameters that ultimately trigger the integer overflow condition.