CVE-2024-45829

Executive Summary

CVE-2024-45829 is an Out-of-bounds Read vulnerability affecting Sharp and Toshiba Tec Multifunction Printers (MFPs). The flaw exists in a web page used to download data, where query parameters in HTTP requests are improperly processed. A crafted HTTP request can trigger an out-of-bounds read, potentially causing the affected device to crash. This vulnerability has a CVSS score of 4.9 (Medium) and currently has no known public exploit or patch. The EPSS score is 0.0%, indicating a low probability of exploitation in the wild at this time.

CVSS Breakdown & Threat Level

• CVSS Score: 4.9 (Medium)
• Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
• Attack Vector: Network (AV:N) – The vulnerability can be exploited remotely over the network.
• Attack Complexity: Low (AC:L) – No special conditions are required for exploitation.
• Privileges Required: None (PR:N) – No authentication is needed.
• User Interaction: None (UI:N) – The attacker does not need to interact with any user.
• Scope: Unchanged (S:U) – The impact is confined to the vulnerable component.
• Confidentiality Impact: None (C:N) – No data is exposed.
• Integrity Impact: None (I:N) – No data is modified.
• Availability Impact: High (A:H) – Successful exploitation can cause a denial of service (crash).

Threat Level: Medium. While the availability impact is high, the lack of public exploit code and low EPSS score reduce the immediate risk. However, the unpatched status and network-based attack vector make it a concern for enterprise environments.

Deep Dive & Mechanics

The vulnerability resides in a web page component of Sharp and Toshiba Tec MFPs that handles data download requests. The application fails to properly validate the length of query parameters before reading them into a buffer. By sending a specially crafted HTTP request with an oversized or malformed query parameter, an attacker can cause the application to read beyond the allocated buffer boundaries.

This out-of-bounds read can lead to:

• Denial of Service (DoS): The most likely outcome is a crash of the affected service or the entire device.
• Information Disclosure (Potential): In some cases, out-of-bounds reads can leak sensitive memory contents, though the CVSS score indicates no confidentiality impact in this specific case.

The root cause is a lack of bounds checking on user-supplied input in the query string processing logic. The vulnerable code likely uses a function like strcpy, sprintf, or a custom parser that does not verify the input length against the destination buffer size.

Vulnerable vs. Patched Code

Since no patch or specific version information is available, a generic example is provided.

Vulnerable Code (C-like pseudocode):

void handle_download_request(char *query) {
    char buffer[256];
    // Vulnerable: no bounds checking
    strcpy(buffer, query);
    // Process buffer...
}

Patched Code (C-like pseudocode):

void handle_download_request(char *query) {
    char buffer[256];
    // Patched: use strncpy with length limit
    strncpy(buffer, query, sizeof(buffer) - 1);
    buffer[sizeof(buffer) - 1] = '\0';
    // Process buffer...
}

The patched version uses strncpy to limit the number of bytes copied to the buffer, preventing an out-of-bounds read.

Exploitation & Lab Setup

Red Team

Lab Setup:

1. Obtain a vulnerable Sharp or Toshiba Tec MFP (or use a firmware emulator like QEMU).
2. Set up a network connection to the device.
3. Use a tool like curl or a custom Python script to send crafted HTTP requests.

Exploitation Steps:

1. Identify the vulnerable endpoint (e.g., /download?file=...).
2. Craft a request with an excessively long query parameter:

   curl "http://<MFP_IP>/download?file=$(python3 -c 'print("A"*10000)')"
   

3. Monitor the device for crashes or denial of service.

Expected Outcome: The MFP web service crashes, potentially requiring a manual reboot.

Blue Team

Detection:

• Monitor for HTTP requests with abnormally long query strings targeting MFP devices.
• Use network intrusion detection systems (NIDS) to flag suspicious patterns.

Mitigation:

• Isolate MFPs on a separate VLAN with strict access controls.
• Apply vendor patches as soon as they become available.
• Implement web application firewalls (WAF) to filter oversized requests.

Indicators of Compromise (IOCs)

• Network IOCs:

  • HTTP requests with query parameters exceeding 1024 characters.
  • Repeated requests to /download or similar endpoints with varying long strings.
  • Source IPs performing reconnaissance on MFP web interfaces.

• System IOCs:

  • MFP web service crashes or unexpected reboots.
  • Error logs indicating buffer overflow or segmentation faults.
  • Memory dumps showing repeated patterns (e.g., "AAAA...") in the crash data.

Detection Engineering

YARA Rule

rule CVE_2024_45829_OutOfBoundsRead {
    meta:
        description = "Detects exploit attempts for CVE-2024-45829 in HTTP traffic"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "https://nvd.nist.gov/vuln/detail/CVE-2024-45829"
    strings:
        $http_get = "GET /download?file=" ascii nocase
        $long_param = /[?&]file=[A-Za-z0-9%]{1024,}/ ascii
    condition:
        $http_get and $long_param
}

Sigma Rule

title: CVE-2024-45829 Exploit Attempt
id: 8a3f7c2e-5d1b-4a9f-8c6e-2b7d3f1a0e4c
status: experimental
description: Detects HTTP requests with excessively long query parameters targeting Sharp/Toshiba MFPs
author: Valters IT
date: 2025-04-10
references:
    - https://nvd.nist.gov/vuln/detail/CVE-2024-45829
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-method: 'GET'
        cs-uri-query|contains: '/download?file='
        cs-uri-query|length: >= 1024
    condition: selection
falsepositives:
    - Legitimate large file downloads (unlikely)
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2024-45829 - Sharp/Toshiba MFP Out-of-bounds Read Attempt"; flow:to_server; content:"GET"; http_method; content:"/download?file="; http_uri; pcre:"/[?&]file=[A-Za-z0-9%]{1024,}/"; classtype:attempted-dos; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Isolate MFPs: Place all Sharp and Toshiba Tec MFPs on a separate VLAN with restricted access.
2. Monitor Logs: Enable detailed logging on MFP web interfaces and monitor for suspicious requests.
3. Apply Workarounds: If possible, disable the vulnerable web page or restrict access via firewall rules.

Long-term Fix:

• Await an official patch from Sharp or Toshiba Tec. Contact vendor support for updates.
• Once a patch is released, apply it to all affected devices immediately.

Compensating Controls:

• Deploy a Web Application Firewall (WAF) to filter oversized query parameters.
• Use network segmentation to limit exposure of MFPs to untrusted networks.
• Implement intrusion prevention systems (IPS) with signatures for this vulnerability.

Valters IT
Senior DevSecOps & Cyber Threat Intelligence Expert