header-logo
Suggest Exploit
vendor:
FreeBSD
by:
PT Security
7,5
CVSS
HIGH
Denial of Service (DoS)
400
CWE
Product Name: FreeBSD
Affected Version From: 9.3
Affected Version To: 10.2
Patch Exists: YES
Related CWE: CVE-2016-1879
CPE: o:freebsd:freebsd
Metasploit: https://www.rapid7.com/db/vulnerabilities/freebsd-vid-78f06a6c-600a-11e6-a6c3-14dae9d210b8/
Other Scripts: N/A
Tags: N/A
CVSS Metrics: N/A
Nuclei References: N/A
Nuclei Metadata: N/A
Platforms Tested: None
2016

SCTP Vulnerability in FreeBSD Systems

SCTP (stream control transmission protocol) is a transport-layer protocol designed to transfer signaling messages in an IP environment. This vulnerability threatens FreeBSD systems (versions 9.3, 10.1, and 10.2) if they support SCTP and IPv6 (default configuration). To exploit this flaw, a malefactor needs to send a specially crafted ICMPv6 message. And if he succeeds, he can conduct a DoS attack. Denial of service is caused by improper check of the length of an SCTP packet header received from the ICMPv6 error message. If the target recipient is unavailable, the router can generate an error message and send it to the sender via ICMPv6. This ICMPv6 packet includes the original IPv6 packet where the Next Header field indicates how SCTP is encapsulated. When the kernel receives the error message via ICMPv6, it transfers the upper-level protocol packet to a necessary parser (sctp6_ctlinput()). The SCTP parser considers the incoming header has the required length, tries to copy it using m_copydata(), which has offset values and the number of bytes. Since a twelve-byte chunk is expected, if the attacker sends a packet with an eleven-byte header, a NULL pointer is dereferenced causing kernel panic.

Mitigation:

Upgrade to the latest version of FreeBSD.
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>11012</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>

        
    </main>
</body>
</html>

Navigation

Suggest Exploit

Services By CQR