CVE-2024-41710

What it actually does

The flaw is an argument/command injection issue in Mitel 6800 Series, 6900 Series, 6900w Series SIP Phones, and the 6970 Conference Unit through R6.4.0.HF1 / R6.4.0.136. An attacker who already has administrative privileges and network adjacency to the phone can supply malicious boot-time parameters that are not properly sanitized. When the device boots, those parameters can be interpreted as command arguments or shell syntax, allowing arbitrary operating-system command execution in the context of the phone system. Successful exploitation can compromise confidentiality, integrity, and availability of the device, including configuration theft, firmware or startup modification, call disruption, and potential use of the phone as a foothold on a voice network.

Why it matters to the business

Compromised SIP phones can disrupt business communications, expose call metadata or sensitive conversations, enable unauthorized configuration changes, and provide an attacker with a pivot point into segmented voice or management networks. Although exploitation requires administrative access, this vulnerability is listed in CISA KEV with active exploitation observed in the wild, and the CISA remediation deadline was 2025-03-05, so unpatched devices should be treated as high-priority legacy exposure. Organizations with large deployments of affected desk phones or conference units may face broad operational impact because remediation often requires coordinated firmware rollout, reboot windows, and validation across voice infrastructure.

How an attack unfolds

An attacker first gains administrative access to an affected Mitel SIP phone, commonly through stolen admin credentials, weak/default credentials, exposed management interfaces, or compromise of provisioning infrastructure. From a network position that can reach the phone management interface or provisioning path, the attacker modifies a boot-time configuration value so that it contains shell metacharacters or injected command arguments. The attacker then causes or waits for a device reboot. During startup, the vulnerable firmware processes the unsanitized parameter and executes the injected command as part of the phone operating environment. Post-exploitation activity may include downloading tools, enabling persistence through modified configuration or startup behavior, changing SIP settings, harvesting credentials or call data, disrupting phone service, or using the phone to scan and reach other systems on the voice VLAN. Public reporting and KEV status indicate active exploitation activity associated with Mitel SIP phone argument injection, so detection should assume opportunistic exploitation is plausible where vulnerable devices are reachable and administratively exposed.

How to fix it

Upgrade affected Mitel SIP phones to a vendor-fixed firmware release newer than R6.4.0.HF1 / R6.4.0.136 according to Mitel guidance for the specific phone model. Prioritize internet-exposed, management-exposed, and high-value conference-room devices first. If immediate upgrade is not possible, restrict phone management interfaces to dedicated administration networks, block access from user VLANs and untrusted networks, enforce strong unique admin credentials, disable unused management services, validate provisioning server integrity, and prevent phones from making arbitrary outbound connections to the internet. Reboot devices only after confirming they will load trusted configuration. Review the provided asset/package mapping before applying non-Mitel package fixes: the supplied fixed-version metadata references bytecodealliance/wasmtime commit 9e2adfb34531610d691f74dd3f559bc5b800eb02, which does not align with the Mitel SIP phone vulnerability description and should be treated as a data-correlation issue unless independently confirmed relevant.

How to confirm the fix worked

Confirm exposure by inventorying Mitel 6800 Series, 6900 Series, 6900w Series, and 6970 Conference Unit devices and recording their exact firmware versions. Devices running through R6.4.0.HF1 / R6.4.0.136 should be considered vulnerable. After remediation, verify from the phone UI, central management platform, provisioning records, or device inventory that each phone reports a fixed firmware version newer than the vulnerable release. Confirm management access is limited to approved administration networks and that default or shared administrator passwords are not in use. Validate provisioning files and boot parameters for absence of shell metacharacters or unexpected command-like content. Perform controlled reboot testing on a sample of upgraded devices to ensure they boot cleanly, retain trusted configuration, and do not generate suspicious outbound network connections.

Typical attack path

1. Identify affected Mitel 6800 Series, 6900 Series, 6900w Series, or 6970 Conference Unit devices on a reachable voice or management network.
2. Obtain administrative access to the phone or its provisioning workflow through credential theft, reused/default credentials, exposed admin services, or compromised provisioning infrastructure.
3. Submit or modify a vulnerable boot-time configuration parameter containing command separators, shell metacharacters, or injected arguments.
4. Trigger a reboot or wait for the next normal reboot so the malicious parameter is processed during startup.
5. Achieve arbitrary command execution on the phone in the system context.
6. Establish persistence, alter SIP/provisioning settings, download additional tooling, collect configuration or credentials, disrupt service, or pivot within the voice network.

How to detect it

To determine whether exploitation already occurred, collect and review phone syslog, central phone-management logs, provisioning server logs, web administration logs, DHCP/TFTP/HTTP provisioning access logs, firewall logs, DNS logs, proxy logs, and network telemetry from voice VLANs. Focus on the period before patching and around device reboots, because exploitation is triggered during boot processing. Look for administrative logins from unusual hosts, unexpected configuration edits, provisioning file changes, abnormal reboot events, and configuration values containing shell metacharacters such as semicolons, pipes, backticks, command substitution, redirection, or chained commands. Compare current phone configuration and provisioning templates against known-good baselines. Investigate any phone initiating outbound connections inconsistent with normal SIP, NTP, DNS, provisioning, or management behavior, especially downloads from external HTTP/HTTPS servers, TFTP/FTP transfers to unknown destinations, SSH/Telnet activity, or connections to unusual high ports. On provisioning infrastructure, search historical versions of phone configuration files for injected command syntax. If device-level shell access or forensic capture is available, review startup scripts, temporary directories, modified configuration files, unauthorized binaries, and evidence of tools such as wget, curl, busybox, nc, telnetd, dropbear, or reverse shells. Because exploitation has been observed in the wild, absence of endpoint telemetry on phones should not be treated as proof of no compromise; corroborate with network and provisioning logs.

• ;wget
• ;curl
• |wget
• |curl
• `wget
• `curl
• $(wget
• $(curl
• /bin/sh -c
• /bin/busybox
• busybox wget
• busybox nc
• /tmp/
• /var/tmp/
• /dev/shm/
• nc -e
• netcat -e
• telnetd
• dropbear
• chmod +x
• tftp -g
• ftpget
• /etc/init.d/
• /etc/rc.local
• reboot reason
• configuration changed
• admin login
• provisioning file updated
• User-Agent: Wget
• User-Agent: curl

What your security team should do

• Treat this as urgent for affected Mitel SIP phone fleets because it is in CISA KEV, has active exploitation reported, has a substantial EPSS score, and the KEV due date has already passed.
• Create or refresh an inventory of all Mitel 6800, 6900, 6900w, and 6970 devices, including firmware version, management exposure, provisioning source, and network segment.
• Patch or replace all devices running through R6.4.0.HF1 / R6.4.0.136, prioritizing devices reachable from less-trusted networks or used in sensitive locations.
• Restrict administrative interfaces to a dedicated management network or jump host and block phone administration from general user networks and the internet.
• Rotate phone administrator credentials and provisioning credentials, especially where shared, default, or long-lived credentials may have been used.
• Review provisioning server files, recent configuration changes, and device reboot history for suspicious injected commands or unauthorized modifications.
• Monitor voice VLAN egress for unexpected DNS, HTTP/HTTPS, TFTP, FTP, SSH, Telnet, or reverse-shell style traffic from phone IP addresses.
• Hunt for evidence of compromise before and after patching because upgrading firmware may remove the vulnerability but not fully explain prior unauthorized configuration changes.
• Resolve the product-mapping inconsistency in vulnerability management systems if this CVE is associated with unrelated Wasmtime package metadata.