CVE-2018-18928 in International Components for Unicode
Summary
by MITRE
International Components for Unicode (ICU) for C/C++ 63.1 has an integer overflow in number::impl::DecimalQuantity::toScientificString() in i18n/number_decimalquantity.cpp.
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Analysis
by VulDB Data Team • 06/04/2023
The vulnerability identified as CVE-2018-18928 resides within the International Components for Unicode (ICU) library version 63.1, specifically affecting the C/C++ implementation. This issue manifests as an integer overflow within the number::impl::DecimalQuantity::toScientificString() function located in the i18n/number_decimalquantity.cpp source file. The ICU library serves as a foundational component for internationalization and localization tasks across numerous software applications, making this vulnerability particularly concerning due to its potential widespread impact. The integer overflow occurs during the conversion of decimal quantities to scientific string representation, which is a common operation in numerical formatting and display functions.
The technical flaw represents a classic integer overflow condition where an arithmetic operation attempts to create a result that exceeds the maximum value that can be stored in the allocated storage space. In this case, the overflow specifically affects the handling of scientific notation conversion within the ICU library's number formatting capabilities. When processing certain numerical inputs, the function fails to properly validate or handle the mathematical operations involved in converting decimal quantities to scientific string format, leading to potential buffer overflows or memory corruption scenarios. This type of vulnerability falls under CWE-190, which specifically addresses integer overflow conditions, and can be categorized under the broader ATT&CK technique T1059.001 for execution through command-line interfaces when exploited in certain contexts.
The operational impact of this vulnerability extends beyond simple computational errors, potentially enabling attackers to execute arbitrary code or cause application crashes through carefully crafted input data. Since ICU is widely used across various software platforms including web browsers, operating systems, and enterprise applications, a successful exploitation could affect numerous end-user systems and server environments. The vulnerability is particularly dangerous in environments where applications process untrusted input data through ICU's number formatting functions, as attackers could manipulate numerical inputs to trigger the overflow condition and subsequently exploit the resulting memory corruption. The attack surface is broad given ICU's integration into major software ecosystems, including but not limited to Microsoft Windows, Google Chrome, and various enterprise applications that rely on proper internationalization libraries.
Mitigation strategies should prioritize immediate patching of affected ICU library versions to the latest releases that contain the fix for this integer overflow vulnerability. Organizations should conduct comprehensive vulnerability assessments to identify all systems and applications that utilize ICU 63.1 or earlier versions, particularly focusing on applications handling numerical data from external sources. Additional defensive measures include implementing input validation and sanitization for numerical data processed through ICU functions, employing address space layout randomization (ASLR) and data execution prevention (DEP) mechanisms, and monitoring application logs for unusual numerical processing patterns that might indicate exploitation attempts. Security teams should also consider network segmentation and access controls to limit the potential impact of any successful exploitation, while maintaining regular updates to all third-party libraries and components to prevent similar vulnerabilities from being introduced into the system landscape.