CVE-2017-15396 in International Components for Unicode for C
Summary
by MITRE
A stack buffer overflow in NumberingSystem in International Components for Unicode (ICU) for C/C++ before 60.2, as used in V8 in Google Chrome prior to 62.0.3202.75 and other products, allowed a remote attacker to potentially exploit heap corruption via a crafted HTML page.
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 05/04/2023
The vulnerability CVE-2017-15396 represents a critical stack buffer overflow within the NumberingSystem component of International Components for Unicode (ICU) library version 60.1 and earlier. This flaw exists in the C/C++ implementation of ICU and specifically affects the handling of numeric formatting systems used for internationalization purposes. The vulnerability manifests when processing crafted input data that triggers improper boundary checking during stack memory allocation, creating conditions where attacker-controlled data can overwrite adjacent stack memory locations. This issue was particularly significant because ICU is widely used across numerous software applications and web browsers, making the attack surface extremely broad.
The technical exploitation of this vulnerability occurs through a carefully crafted HTML page that leverages the ICU library's NumberingSystem functionality to trigger the buffer overflow condition. When a victim's browser processes such malicious content, the flaw allows an attacker to manipulate stack memory layout and potentially execute arbitrary code with the privileges of the affected application. The vulnerability stems from inadequate input validation and memory boundary checking within the ICU library's numeric formatting routines, specifically in how it handles complex number representations and formatting specifications. This type of flaw maps directly to CWE-121 Stack-based Buffer Overflow, which is classified as a common weakness in software security practices. The attack vector is particularly dangerous because it requires no user interaction beyond visiting a malicious webpage, making it a prime candidate for drive-by exploitation techniques.
The operational impact of CVE-2017-15396 extends far beyond the immediate browser environment, as ICU is integrated into numerous applications including web browsers, operating systems, and enterprise software platforms. The vulnerability affects Google Chrome versions prior to 62.0.3202.75, which means that users running older versions were at risk of heap corruption attacks that could lead to complete system compromise. The exploitation chain typically follows the ATT&CK framework pattern of initial access through web-based malicious content, followed by privilege escalation and code execution. Security researchers noted that the vulnerability was particularly concerning because it could be exploited in the context of a web browser's sandboxed environment, potentially allowing attackers to bypass security boundaries and escalate privileges. The heap corruption aspect of this vulnerability makes it especially dangerous as it can lead to unpredictable behavior and memory corruption that may be difficult to detect and analyze.
Mitigation strategies for CVE-2017-15396 primarily involve updating to ICU version 60.2 or later, which includes proper boundary checking and memory management fixes. System administrators should prioritize updating Google Chrome to version 62.0.3202.75 or higher to address the vulnerability in the V8 JavaScript engine. Organizations should also implement network-based security controls such as web application firewalls and content filtering systems to block malicious HTML content. Additionally, browser hardening measures including sandboxing, strict content security policies, and disabling unnecessary browser features can reduce the attack surface. The vulnerability demonstrates the critical importance of keeping internationalization libraries updated, as these components are often overlooked in security assessments despite their widespread use. Security monitoring should include detection of unusual memory access patterns and potential buffer overflow indicators in applications that use ICU libraries. Organizations should also consider implementing automated patch management systems to ensure timely deployment of security updates across all affected systems and applications.