Microsoft Word unchecked boundary condition vulnerability

vendor:

Microsoft Office

by:

naveed afzal

5.5

CVSS

MEDIUM

Unchecked boundary condition

119

CWE

Product Name: Microsoft Office

Affected Version From: Microsoft Word 2003, 2002, 2000

Affected Version To:

Patch Exists: NO

Related CWE:

CPE:

Metasploit:

Other Scripts:

Platforms Tested:

Microsoft Word unchecked boundary condition vulnerability

One of the functions in mso.dll (older versions mso9.dll) cannot properly handle the specially crafted files causing invalid memory access and in some cases arbitrary overwrites. The exported function LsCreateLine (entry: mso_203) contains a boundary error while parsing certain specially crafted .DOC files, resulting in an invalid memory access. Following proof of concept code generates a .doc file, opening the file will cause an access violation in mso.dll. Code execution is possible if 4-bytes of arbitrary memory is overwritten. Apparently, this is not specific to MS Word only but other Office products are also vulnerable which use these functions. No other user interaction required in order to trigger the vulnerability.

Mitigation:

Apply the latest security patches and updates for Microsoft Office.

Source

Exploit-DB raw data:

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <meta name="robots" content="noindex, nofollow">
    <title>502 Hosting Server Connect Timeout | Sucuri Website Firewall</title>
    <!--
        Base origin-error page (502/504). lualibs/error_pages.lua fills the double-brace placeholders
        per $whitelabel at request time; init.lua substitutes the server id at load. Keep it
        self-contained: no external stylesheet, script, font, CSS import or remote image
        (tests/rules/71-error-pages-self-contained.sh).
    -->
    <style>
        :root {
            --accent: #3b7a26;
        }

        * {
            box-sizing: border-box;
        }

        html {
            -webkit-text-size-adjust: 100%;
        }

        body {
            margin: 0;
            background: #f4f5f7;
            color: #1d2330;
            font: 16px/1.55 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
        }

        a {
            color: var(--accent);
        }

        p {
            margin: 0 0 10px;
        }

        .wrap {
            max-width: 760px;
            margin: 0 auto;
            padding: 32px 16px 48px;
        }

        .product {
            margin: 0 0 20px;
            font-size: 14px;
            font-weight: 600;
            letter-spacing: .02em;
            color: var(--accent);
        }

        .card {
            padding: 28px 24px;
            background: #fff;
            border: 1px solid #e1e4ea;
            border-radius: 10px;
        }

        h1 {
            margin: 0 0 6px;
            font-size: 26px;
            line-height: 1.25;
        }

        h2 {
            margin: 24px 0 8px;
            font-size: 17px;
        }

        .lead {
            margin: 0 0 4px;
            font-size: 18px;
            color: #414a5a;
        }

        .retry {
            margin: 0;
            color: #5b6475;
        }

        /* You -> Firewall -> Hosting diagram */
        .flow {
            display: flex;
            align-items: flex-start;
            justify-content: space-between;
            gap: 8px;
            margin: 28px 0;
            padding: 0;
            list-style: none;
        }

        .node {
            flex: 0 0 auto;
            width: 132px;
            text-align: center;
            font-size: 14px;
            font-weight: 600;
        }

        .icon {
            position: relative;
            display: inline-flex;
            align-items: center;
            justify-content: center;
            width: 64px;
            height: 64px;
            margin-bottom: 6px;
            border-radius: 50%;
        }

        .icon svg {
            width: 32px;
            height: 32px;
            fill: none;
            stroke: currentColor;
            stroke-width: 1.8;
            stroke-linecap: round;
            stroke-linejoin: round;
        }

        .ok-node .icon {
            background: #e7f4ea;
            color: #2f7d3c;
        }

        .fail-node,
        .fail-node .icon {
            color: #c0362c;
        }

        .fail-node .icon {
            background: #fdebea;
        }

        .badge {
            position: absolute;
            right: -2px;
            bottom: -2px;
            width: 22px;
            height: 22px;
            border-radius: 50%;
            color: #fff;
            font-size: 13px;
            line-height: 22px;
        }

        .badge.ok {
            background: #2f7d3c;
        }

        .badge.fail {
            background: #c0362c;
        }

        /* Connector, vertically centred on the 64px icons */
        .link {
            flex: 1 1 auto;
            height: 2px;
            margin-top: 31px;
            background: #c9ced8;
        }

        .link.broken {
            background: repeating-linear-gradient(90deg, #c0362c 0 6px, transparent 6px 11px);
        }

        dl {
            display: grid;
            grid-template-columns: max-content 1fr;
            gap: 4px 16px;
            margin: 0;
            padding: 14px 16px;
            background: #f7f8fa;
            border-radius: 8px;
            font-size: 15px;
        }

        dt {
            color: #5b6475;
        }

        dd {
            margin: 0;
            font-weight: 600;
            overflow-wrap: anywhere;
        }

        ul.causes {
            margin: 0;
            padding-left: 20px;
        }

        footer {
            margin-top: 20px;
            font-size: 13px;
            color: #6b7383;
            text-align: center;
        }

        @media (max-width: 520px) {
            .wrap {
                padding: 20px 16px 32px;
            }

            .card {
                padding: 20px 16px;
            }

            h1 {
                font-size: 22px;
            }

            .flow {
                gap: 4px;
            }

            .node {
                flex: 1 1 0;
                width: auto;
                min-width: 0;
                font-size: 12px;
                line-height: 1.3;
            }

            /* Connector, vertically centred on the 52px icons */
            .link {
                flex: 0 0 14px;
                margin-top: 25px;
            }

            .icon {
                width: 52px;
                height: 52px;
            }

            .icon svg {
                width: 26px;
                height: 26px;
            }
        }
    </style>
</head>
<body>
    <main class="wrap">
        <p class="product">Sucuri Website Firewall</p>

        <div class="card">
            <h1>Hosting Server Connect Timeout</h1>
            <p class="lead">HTTP 502 &mdash; Unable to Connect to the Origin Server</p>
            <p class="retry">Please try again in a few minutes.</p>

            <ol class="flow" aria-label="Connection path">
                <li class="node ok-node">
                    <span class="icon">
                        <svg viewBox="0 0 24 24" aria-hidden="true">
                            <circle cx="12" cy="8" r="4"/>
                            <path d="M4 21c0-4.4 3.6-8 8-8s8 3.6 8 8"/>
                        </svg>
                        <span class="badge ok" aria-hidden="true">&#10003;</span>
                    </span><br>
                    You
                </li>
                <li class="link" aria-hidden="true"></li>
                <li class="node ok-node">
                    <span class="icon">
                        <svg viewBox="0 0 24 24" aria-hidden="true">
                            <path d="M12 2 4 5v6c0 5 3.4 9.3 8 11 4.6-1.7 8-6 8-11V5z"/>
                        </svg>
                        <span class="badge ok" aria-hidden="true">&#10003;</span>
                    </span><br>
                    Sucuri Firewall
                </li>
                <li class="link broken" aria-hidden="true"></li>
                <li class="node fail-node">
                    <span class="icon">
                        <svg viewBox="0 0 24 24" aria-hidden="true">
                            <rect x="4" y="3" width="16" height="7" rx="1.5"/>
                            <rect x="4" y="14" width="16" height="7" rx="1.5"/>
                            <path d="M8 6.5h.01M8 17.5h.01"/>
                        </svg>
                        <span class="badge fail" aria-hidden="true">&#10005;</span>
                    </span><br>
                    Hosting Timeout
                </li>
            </ol>

            <h2>Error details</h2>
            <dl>
                <dt>Error code</dt>
                <dd>HTTP 502</dd>
                <dt>Error message</dt>
                <dd>Backend or gateway connection timeout.</dd>
                <dt>Server ID</dt>
                <dd>14012</dd>
            </dl>

            <h2>What's going on?</h2>
            <ul class="causes">
                <li>The origin server might be down</li>
                <li>The Sucuri network might be blocked by the origin&#39;s firewall</li>
            </ul>

            <h2>What can I do to fix it?</h2>
            <p>
                If you are just visiting the site, wait a bit and it should be back soon.
                We apologize for the inconvenience.
            </p>
            <p>
                If you own the website, check with your hosting company that your server is up and
                running and that they have <a href="https://docs.sucuri.net/website-firewall/troubleshooting/backend-timeout-message/">our firewall IPs allowlisted</a>.
            </p>
            <p>If the problem persists, open a ticket on our <a href="https://support.sucuri.net">support page</a> and we will help you troubleshoot.</p>
        </div>

        <footer>&copy; Sucuri Inc. All rights reserved. &middot; <a href="https://sucuri.net/privacy/">Privacy Policy</a></footer>
    </main>
</body>
</html>