CVE-2017-5030

What Is Google Chromium V8?

Google V8 is the open-source JavaScript and WebAssembly engine used in Google Chrome, Microsoft Edge (Chromium-based), Opera, and all Electron-based desktop applications. V8 compiles JavaScript to native machine code using the Turbofan JIT (just-in-time) compiler, enabling high-performance execution of complex web applications. Because V8 processes untrusted JavaScript from every website a user visits, vulnerabilities in V8 are browser renderer exploits — enabling arbitrary code execution in the renderer process when a user visits a malicious page. Browser exploits are typically chained with sandbox escapes to achieve full OS code execution.

Overview

CVE-2017-5030 is a memory corruption vulnerability in the Google Chromium V8 engine — specifically an out-of-bounds read (CWE-125) in the Turbofan JIT compiler — that allows a remote attacker to execute arbitrary code in the Chrome renderer process via a crafted HTML page. This vulnerability could affect all Chromium-based browsers including Google Chrome, Microsoft Edge, and Opera. Fixed in Chrome 57.0.2987.98 (March 2017). CISA added CVE-2017-5030 to the KEV catalog in June 2022.

Affected Versions

Technical Details

Root Cause: Out-of-Bounds Read in V8 Turbofan JIT

CVE-2017-5030 is an out-of-bounds read vulnerability (CWE-125) in V8's Turbofan JIT compiler — Chrome's optimizing compiler that generates native machine code from JavaScript. JIT compiler vulnerabilities are a primary category of browser renderer exploit because:

1. JIT compilers perform complex analysis and optimization passes on attacker-controlled JavaScript code
2. Subtle edge cases in optimization logic can result in memory accesses outside intended bounds
3. Out-of-bounds reads can be used to leak memory layout information (defeating ASLR) and combined with write primitives for full exploit chains

A crafted HTML page containing specific JavaScript can trigger the V8 out-of-bounds read, leading to memory corruption that is exploitable for arbitrary code execution within the Chrome renderer sandbox.

Renderer sandbox context: CVE-2017-5030 achieves code execution in the Chrome renderer process, which is sandboxed. To achieve full OS compromise, attackers typically chain browser renderer exploits with sandbox escape vulnerabilities (such as Windows kernel or Chrome browser process exploits). Browser exploit chains sold in the commercial exploit market commonly pair a V8 renderer bug with a sandbox escape.

Attack Characteristics

Exploitation Context

• Drive-by download attacks: V8 vulnerabilities are prime candidates for watering hole attacks and malicious advertisement injection (malvertising); victims need only visit a page hosting the exploit — no file download or user action beyond browsing is required
• State-sponsored targeting: Multiple nation-state groups (including Israeli NSO Group's Pegasus for mobile, and other commercial exploit vendors) develop and use Chrome V8 exploits against high-value targets; CVE-2017-5030's KEV addition reflects confirmed targeted use
• Exploit broker market: Full Chrome renderer + sandbox escape chains were valued at $1M+ on the commercial exploit market in 2017; KEV browser vulnerabilities like CVE-2017-5030 represent the foundation of those exploit chains
• Cross-browser impact: V8 vulnerabilities potentially affect all Chromium-based browsers (Chrome, Edge, Opera, Vivaldi) and Electron apps; the attack surface is enormous given Chrome's dominant browser market share
• CISA KEV (2022): Added June 8, 2022 alongside CVE-2017-5070 (V8 type confusion) — both Chrome V8 vulnerabilities represent confirmed exploitation in targeted attack campaigns

Remediation

1. Update Chrome and all Chromium-based browsers — ensure Chrome is at version 57.0.2987.98 or later; enable Chrome auto-update to ensure future vulnerabilities are patched promptly. Modern Chrome versions receive continuous security updates.

2. Enable Google Chrome auto-update — Chrome's built-in auto-update mechanism is the primary defense against browser vulnerabilities; verify it is not disabled by enterprise policy or AV software interference.

3. Apply Windows/OS updates — browser sandbox escapes often exploit OS kernel vulnerabilities; keeping the underlying OS patched reduces the impact of browser renderer compromises.

4. Use Chrome Site Isolation — Chrome's Site Isolation feature (--site-per-process) limits the impact of renderer exploits by preventing cross-origin data leakage; this has been the default in Chrome since version 67.

5. Audit browser versions across the fleet — use endpoint management tools to identify systems running outdated Chrome versions; browser version enforcement is a high-value security control given the frequency of V8 exploitation.