CVE-2017-15422 in International Components for Unicode
Summary
by MITRE
Integer overflow in international date handling in International Components for Unicode (ICU) for C/C++ before 60.1, as used in V8 in Google Chrome prior to 63.0.3239.84 and other products, allowed a remote attacker to perform an out of bounds memory read via a crafted HTML page.
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Analysis
by VulDB Data Team • 05/06/2023
The vulnerability CVE-2017-15422 represents a critical integer overflow flaw within the International Components for Unicode (ICU) library, specifically affecting the C/C++ implementation prior to version 60.1. This issue manifests in the handling of international date formats and has far-reaching implications for software systems that rely on ICU for internationalization capabilities. The vulnerability is particularly concerning because it enables remote code execution through web browsers, with Google Chrome being one of the primary affected products where the issue was present before version 63.0.3239.84.
The technical nature of this vulnerability stems from improper integer overflow handling during date parsing operations within the ICU library. When processing international date formats, the library fails to properly validate integer values, allowing maliciously crafted input to cause arithmetic overflow conditions. This overflow results in incorrect memory calculations that ultimately lead to out-of-bounds memory reads. The flaw occurs specifically during the parsing of international date strings where the system attempts to calculate buffer sizes or array indices based on potentially malicious input, creating a scenario where legitimate memory access operations extend beyond allocated boundaries.
The operational impact of this vulnerability extends beyond simple memory corruption, as it creates a remote code execution vector that can be exploited through web browsers. Attackers can craft malicious HTML pages containing specially formatted international date strings that trigger the integer overflow condition when processed by vulnerable versions of ICU. This allows adversaries to read arbitrary memory locations, potentially exposing sensitive data or enabling further exploitation techniques. The vulnerability is particularly dangerous because it operates at the library level, meaning that any application or browser engine using ICU for internationalization is susceptible to this attack vector.
The exploitation of this vulnerability aligns with several ATT&CK framework techniques including T1059 for remote code execution and T1203 for exploitation for privilege escalation. From a CWE perspective, this represents a classic integer overflow vulnerability (CWE-190) that leads to memory corruption issues. The vulnerability demonstrates how seemingly benign internationalization features can become attack surfaces when proper input validation and overflow protection mechanisms are absent. Organizations using affected versions of ICU, particularly those with web browsers or applications that process international date formats, face significant risk of compromise.
Mitigation strategies for CVE-2017-15422 primarily involve updating to patched versions of the ICU library, specifically version 60.1 or later, and ensuring that affected software components such as Google Chrome are updated to versions that include the necessary fixes. System administrators should prioritize patching across all affected applications that utilize ICU for internationalization, particularly web browsers and applications handling user-supplied date data. Additionally, implementing network-level protections such as web application firewalls and content filtering systems can provide additional defense-in-depth measures. Organizations should also consider monitoring for suspicious date-related data processing patterns and implementing proper input sanitization techniques to reduce the attack surface even when dealing with unpatched systems. The vulnerability highlights the importance of thorough security testing for internationalization libraries and the need for robust integer overflow protection mechanisms in widely-used software components.