CVE-2024-51979: Stack-Based Buffer Overflow Vulnerability

CVE-2024-51979 Overview

CVE-2024-51979 is a stack-based buffer overflow [CWE-121] affecting network printing and multifunction devices from multiple vendors, including Brother, Fujifilm Business Innovation, Konica Minolta, and Ricoh. An authenticated attacker can trigger the overflow by sending a malformed HTTP, HTTPS, or IPP request to TCP ports 80, 443, or 631. The request must contain an empty Origin header and a Referer header whose host value exceeds 64 bytes. Successful exploitation leads to memory corruption on the device with high impact to confidentiality, integrity, and availability.

Critical Impact
Authenticated attackers on the network can corrupt device memory and potentially execute arbitrary code on affected printers by sending a single malformed HTTP, HTTPS, or IPP request.

Affected Products

Brother multifunction printers and network printing devices (see Brother FAQ #00100846, #00100848, #00100620)
Fujifilm Business Innovation multifunction devices (per Fujifilm Security Notice, June 25, 2025)
Konica Minolta and Ricoh printing devices identified in vendor advisories

Discovery Timeline

2025-06-25 - CVE-2024-51979 published to the National Vulnerability Database
2025-06-25 - Vendor advisories released by Brother, Fujifilm, Konica Minolta, and Ricoh; Rapid7 publishes coordinated disclosure research
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2024-51979

Vulnerability Analysis

The flaw is a classic stack-based buffer overflow in the HTTP request parsing logic used by the device's embedded web management and Internet Printing Protocol (IPP) services. When the device processes an incoming request containing an empty Origin header, it takes a code path that copies the host portion of the Referer header into a fixed-size stack buffer of 64 bytes without validating length. Any host value larger than 64 bytes overwrites adjacent stack memory, including saved return addresses and control data.

Because the vulnerable services listen on standard ports 80 (HTTP), 443 (HTTPS), and 631 (IPP), any network-reachable device is exposed. The attacker must first authenticate to the device, which limits blind mass exploitation but does not prevent abuse by insiders, credential-stuffing attackers, or adversaries chaining default credentials.

Root Cause

The vulnerable routine assumes the Referer host value fits within a 64-byte stack buffer and performs a length-unchecked copy operation. The Origin header check acts as a branch condition that steers the request into the vulnerable parsing path, making the empty Origin value a required precondition for triggering the overflow.

Attack Vector

An authenticated attacker sends a crafted HTTP, HTTPS, or IPP request containing an empty Origin header and a Referer header whose host component exceeds 64 bytes. Verified proof-of-concept details are documented in the Rapid7 disclosure research and the BrotherVulnerabilities GitHub repository. No verified public exploit code is referenced in this advisory beyond the disclosure whitepaper.

Detection Methods for CVE-2024-51979

Indicators of Compromise

HTTP, HTTPS, or IPP requests to a printer containing an empty Origin header combined with a Referer header whose host field exceeds 64 bytes
Unexpected reboots, service crashes, or firmware integrity failures on Brother, Fujifilm, Konica Minolta, or Ricoh devices
Authenticated management sessions originating from unexpected internal hosts targeting ports 80, 443, or 631

Detection Strategies

Inspect HTTP and IPP traffic destined for printers and alert on Referer header host values longer than 64 bytes when Origin is empty
Correlate printer authentication events with subsequent malformed request patterns to identify exploitation attempts
Baseline normal management traffic per device and flag deviations in header structure or request frequency

Monitoring Recommendations

Enable syslog or SNMP forwarding from printers into a centralized log platform and monitor for crash, reboot, and authentication anomalies
Restrict management interface access using ACLs or network segmentation and alert on connections from non-administrative subnets
Track firmware versions across the print fleet and alert when devices remain on vulnerable builds after patch release

How to Mitigate CVE-2024-51979

Immediate Actions Required

Apply the firmware updates published by Brother, Fujifilm, Konica Minolta, and Ricoh for each affected model as identified in their advisories
Change all default administrator passwords on printing devices to reduce the value of the authentication precondition
Segment printers onto a dedicated VLAN and block inbound access to ports 80, 443, and 631 from user workstations and untrusted networks

Patch Information

Patched firmware is available through vendor support channels. Reference the Brother FAQ #00100846, Brother FAQ #00100848, Brother FAQ #00100620, Fujifilm Security Notice, Konica Minolta Security Advisory KM-2025-0001, and Ricoh Vulnerability Advisory 2025-000007 for model-specific firmware versions.

Workarounds

Disable the HTTP, HTTPS, and IPP services on affected devices where remote management is not required
Enforce strong, unique administrator credentials and rotate any shared or default accounts used for printer administration
Place printers behind a firewall or reverse proxy that strips or validates Origin and Referer headers before forwarding requests to the device

bash

# Example network ACL restricting printer management ports to an admin subnet
iptables -A FORWARD -s 10.10.50.0/24 -d 10.20.0.0/16 -p tcp -m multiport --dports 80,443,631 -j ACCEPT
iptables -A FORWARD -d 10.20.0.0/16 -p tcp -m multiport --dports 80,443,631 -j DROP