CVE-2024-45062

Executive Summary

CVE-2024-45062 is a critical stack-based buffer overflow vulnerability in OpenPrinting ippusbxd version 1.34. This flaw allows a specially crafted printer supporting IPP-over-USB to trigger a buffer overflow, potentially leading to arbitrary code execution within a privileged service. The attack vector requires physical USB connectivity, making it a high-risk threat in environments where untrusted USB devices can be connected. The vulnerability has a CVSS score of 6.4 (Medium), but the potential for privilege escalation and code execution elevates its severity in operational contexts.

CVSS Breakdown & Threat Level

• CVSS Score: 6.4 (Medium)
• Attack Vector (AV): Physical (AV:P) – Requires USB connection.
• Attack Complexity (AC): Low (AC:L) – No special conditions needed.
• Privileges Required (PR): None (PR:N) – No authentication needed.
• User Interaction (UI): None (UI:N) – No user action required.
• Scope (S): Unchanged (S:U) – Vulnerability does not affect other components.
• Confidentiality (C): High (C:H) – Potential for data exposure.
• Integrity (I): High (I:H) – Potential for data modification.
• Availability (A): High (A:H) – Potential for service disruption.

Threat Level: High. Despite the physical attack vector, the lack of user interaction and the potential for arbitrary code execution in a privileged service make this a critical risk for systems exposed to untrusted USB devices.

Deep Dive & Mechanics

The vulnerability resides in the IPP-over-USB daemon (ippusbxd) used by OpenPrinting to handle printer communication over USB. The daemon parses IPP (Internet Printing Protocol) messages received from USB-connected printers. A stack-based buffer overflow occurs when the daemon processes a specially crafted IPP message with an oversized field, such as a URI or attribute value, without proper bounds checking.

Technical Details:

• The vulnerable function likely uses strcpy() or similar unsafe functions to copy attacker-controlled data into a fixed-size stack buffer.
• By sending a malicious IPP message with a field exceeding the buffer size, an attacker can overwrite the return address and other stack data.
• This allows arbitrary code execution in the context of the ippusbxd service, which typically runs with elevated privileges (e.g., root or lpadmin).

Attack Scenario:

1. An attacker connects a malicious USB device (posing as an IPP-over-USB printer) to the target system.
2. The device sends a crafted IPP message with an oversized field.
3. The ippusbxd daemon processes the message, triggering the buffer overflow.
4. The attacker gains code execution with the privileges of the daemon.

Vulnerable vs. Patched Code

Vulnerable Code (ippusbxd 1.34):

// Example vulnerable function
void process_ipp_message(char *data) {
    char buffer[256];
    // Unsafe copy without bounds checking
    strcpy(buffer, data);
    // ... further processing
}

Patched Code (Hypothetical):

// Patched version with bounds checking
void process_ipp_message(char *data, size_t data_len) {
    char buffer[256];
    if (data_len >= sizeof(buffer)) {
        // Handle error
        return;
    }
    strncpy(buffer, data, sizeof(buffer) - 1);
    buffer[sizeof(buffer) - 1] = '\0';
    // ... further processing
}

Note: No official patch has been released as of this report. The above is a hypothetical fix.

Exploitation & Lab Setup

Red Team

Lab Setup:

1. Target: Linux system with ippusbxd 1.34 installed and running.
2. Attacker: A USB device capable of emulating an IPP-over-USB printer (e.g., using a Raspberry Pi Pico or similar microcontroller).
3. Tools: Python with pyusb library, custom IPP message generator.

Exploitation Steps:

1. Connect the malicious USB device to the target.
2. Send a crafted IPP message with an oversized field (e.g., a URI longer than 256 bytes).
3. The buffer overflow overwrites the return address with a controlled value.
4. Execute shellcode to spawn a reverse shell or escalate privileges.

Example Payload (Python):

import usb.core
import usb.util

# Find the ippusbxd device
dev = usb.core.find(idVendor=0x1234, idProduct=0x5678)
if dev is None:
    raise ValueError("Device not found")

# Craft malicious IPP message
payload = b"A" * 256 + b"\x90" * 100 + shellcode
# Send the payload
dev.write(0x01, payload)

Blue Team

Detection:

• Monitor USB device connections and log all IPP-over-USB traffic.
• Use endpoint detection and response (EDR) tools to detect abnormal process behavior (e.g., ippusbxd crashing or executing shellcode).
• Implement USB device whitelisting to prevent unauthorized devices.

Mitigation:

• Disable ippusbxd if not required.
• Apply input validation and bounds checking in the daemon.
• Use stack canaries and ASLR to mitigate exploitation.

Indicators of Compromise (IOCs)

• File Hashes:
  • ippusbxd binary (v1.34): SHA256 a1b2c3d4e5f6... (example)
• Network Indicators:
  • Unusual IPP-over-USB traffic with oversized fields.
• Process Indicators:
  • ippusbxd process crash or abnormal memory access.
• USB Device Indicators:
  • Unknown USB devices with IPP-over-USB descriptors.

Detection Engineering

YARA Rule

rule CVE_2024_45062_ippusbxd {
    meta:
        description = "Detects potential exploitation of CVE-2024-45062 in ippusbxd"
        author = "Valters IT"
        date = "2025-04-10"
    strings:
        $s1 = "ippusbxd" nocase
        $s2 = "buffer overflow" nocase
        $s3 = "stack" nocase
    condition:
        $s1 and ($s2 or $s3)
}

Sigma Rule

title: CVE-2024-45062 ippusbxd Buffer Overflow
id: 12345678-1234-1234-1234-123456789012
status: experimental
description: Detects potential exploitation of CVE-2024-45062 in ippusbxd
logsource:
    category: process_creation
    product: linux
detection:
    selection:
        Image|endswith: '/ippusbxd'
        CommandLine|contains: 'buffer'
    condition: selection
falsepositives:
    - Legitimate ippusbxd usage
level: high

Suricata Rule

alert tcp any any -> any 631 (msg:"CVE-2024-45062 ippusbxd Buffer Overflow"; flow:to_server; content:"|00 00 00 00|"; depth:4; offset:0; content:"|41 41 41 41|"; distance:0; within:256; classtype:attempted-admin; sid:1000001; rev:1;)

Remediation & Mitigation

1. Immediate Actions:
   • Disable ippusbxd service if not required: systemctl stop ippusbxd && systemctl disable ippusbxd
   • Restrict USB device connections using USBGuard or similar tools.
2. Long-term Fix:
   • Apply input validation and bounds checking in the ippusbxd source code.
   • Monitor for official patches from OpenPrinting.
3. Compensating Controls:
   • Use stack canaries and ASLR.
   • Run ippusbxd in a sandboxed environment with minimal privileges.

Valters IT
Senior DevSecOps & Cyber Threat Intelligence Expert