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CVE-2020-6418 is a type confusion vulnerability in the V8 JavaScript engine used by Google Chrome, affecting versions prior to 80.0.3987.122. The flaw resides in TurboFan, V8’s optimizing compiler, specifically in InferMapsUnsafe() map-reliability analysis. A JSCreate node was incorrectly modeled as not invalidating Map reliability when encountered as a side effect, allowing TurboFan to treat object Maps as reliable after they had actually changed. In practice, a crafted JavaScript sequence involving Reflect.construct() and a Proxy can trigger a Map-changing side effect during optimization, causing required Map checks to be omitted. This can confuse array element types, such as object arrays and double arrays, leading to out-of-bounds access, heap corruption, and a path toward controlled memory manipulation within the V8 sandbox. The vulnerability was reported as exploitable via a crafted HTML page and was observed exploited in the wild.
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2 valid exploits after Mallory filtered fakes, detection scripts, and README-only repos.
This repository contains a single Metasploit module: 'chrome_jscreate_sideeffect.rb', which exploits CVE-2020-6418, a type confusion vulnerability in Google Chrome 80.0.3987.87 (64 bit) on Windows 10 and macOS. The exploit is delivered via a malicious HTTP server that serves a crafted HTML/JavaScript payload to the victim's browser. The JavaScript code manipulates array structures to achieve out-of-bounds read/write, then leverages WebAssembly to allocate RWX memory, into which attacker-supplied shellcode is written and executed. The exploit requires the browser to be run with the '--no-sandbox' flag for successful code execution. The module is operational and provides remote code execution in the context of the Chrome renderer process. The only fingerprintable endpoint is the root path ("/") of the HTTP server set up by the Metasploit module to deliver the exploit. The repository is structured as a typical Metasploit exploit module, written in Ruby, with embedded JavaScript for the browser-side exploit.
This repository contains a proof-of-concept (PoC) exploit for CVE-2020-6418, a type confusion vulnerability in the V8 JavaScript engine (used in Google Chrome). The repository consists of two files: a README.md with environment setup and references, and the main exploit script cve_2020_6418_exploit.js. The exploit script demonstrates how to achieve out-of-bounds (OOB) array access in V8, which is then leveraged to gain arbitrary read/write primitives. Using these primitives, the exploit locates a WebAssembly function's code address and injects native shellcode, ultimately achieving arbitrary code execution. The exploit is operational and demonstrates a full sandbox escape, but does not include a full browser sandbox escape (as noted in the README). No network or file endpoints are hardcoded in the exploit; it is a local, browser-based attack requiring the ability to execute JavaScript in a vulnerable V8 environment.
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6 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.
A publicly known V8 JavaScript engine memory corruption vulnerability referenced as part of a prior Foxit PDF Reader RCE case involving an outdated embedded V8 version.
A prior V8 vulnerability referenced as having a similar Map-inference issue involving JSCreate nodes.
A newer Chromium vulnerability incorporated into the MOONSHINE exploit kit and used in the wild to compromise Android apps with embedded vulnerable Chrome or TBS engines.
A type confusion vulnerability in Google Chrome's V8 engine (Turbofan) caused by incorrect side-effect modeling of JSCreate, which can lead to out-of-bounds access, heap corruption, and exploitation.
Query your assets running an affected version, and investigate the blast radius.
Every observed campaign linking this CVE to a named adversary.
Malware families riding this exploit, with evidence and IOCs.
YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.
Cross-references every affected SKU, including bundled OEM variants.
Community discussion across Reddit, Mastodon, and other social sources.