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Vulnerability record · CVE-2022-29855 · published 11 May 2022

CVE-2022-29855: Mitel 6873i sip firmware vulnerability

Mitel · 6873i Sip Firmware

Mitel 6800 and 6900 Series SIP phone devices through 2022-04-27 have "undocumented functionality." A vulnerability in Mitel 6800 Series and 6900 Series SIP phones excluding 6970, versions 5.1 SP8 (5.1.0.8016) and earlier, and 6.0 (6.0.0.368) through 6.1 HF4 (6.1.0.165), could allow a unauthenticated attacker with physical access to the phone to gain root access due to insufficient access control for test functionality during system startup. A successful exploit could allow access to sensitive information and code execution.

6.8 CVSS 3.1 Medium EPSS 0.74% · top 47.3%
6.8CVSS 3.1 base score, v2 7.2
0.74%EPSS exploitation probability, 30 days
NoNot in CISA KEV
9Affected product versions listed by NVD
10References, 4 tagged exploit
17 Jun 2026Last modified by NVD

Description

Mitel 6800 and 6900 Series SIP phone devices through 2022-04-27 have "undocumented functionality." A vulnerability in Mitel 6800 Series and 6900 Series SIP phones excluding 6970, versions 5.1 SP8 (5.1.0.8016) and earlier, and 6.0 (6.0.0.368) through 6.1 HF4 (6.1.0.165), could allow a unauthenticated attacker with physical access to the phone to gain root access due to insufficient access control for test functionality during system startup. A successful exploit could allow access to sensitive information and code execution.

CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected products

9 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
http://packetstormsecurity.com/files/167547/Mitel-6800-6900-Series-SIP-Phones-Backdoor-Access.html ExploitThird Party AdvisoryVDB Entry
http://seclists.org/fulldisclosure/2022/Jun/32 ExploitMailing ListThird Party Advisory
https://www.mitel.com/support/security-advisories Vendor Advisory
https://www.mitel.com/support/security-advisories/mitel-product-security-advisory-22-0004 Vendor Advisory
https://www.syss.de/pentest-blog/undocumented-functionality-backdoor-in-mitel-desk-phones-syss-2022-021 Third Party Advisory
http://packetstormsecurity.com/files/167547/Mitel-6800-6900-Series-SIP-Phones-Backdoor-Access.html ExploitThird Party AdvisoryVDB Entry
http://seclists.org/fulldisclosure/2022/Jun/32 ExploitMailing ListThird Party Advisory
https://www.mitel.com/support/security-advisories Vendor Advisory
https://www.mitel.com/support/security-advisories/mitel-product-security-advisory-22-0004 Vendor Advisory
https://www.syss.de/pentest-blog/undocumented-functionality-backdoor-in-mitel-desk-phones-syss-2022-021 Third Party Advisory

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

7.2CVE-2024-41710Mitel SIP Phones argument injection in boot processMitel 6800, 6900 and 6900w Series SIP Phones (including the 6970 Conference Unit) through R6.4.0.HF1 fail to sanitize parameters during the boot proc…KEVEPSS 42%analysed8.8CVE-2024-37569Mitel 6869i sip firmware command injection vulnerabilityAn issue was discovered on Mitel 6869i through 4.5.0.41 and 5.x through 5.0.0.1018 devices. A command injection vulnerability exists in the hostname …EPSS 3.2%8.8CVE-2024-37570Mitel 6869i sip firmware command injection vulnerabilityOn Mitel 6869i 4.5.0.41 devices, the Manual Firmware Update (upgrade.html) page does not perform sanitization on the username and path parameters (se…EPSS 1.1%8.1CVE-2020-27639Mitel 6873i sip firmware vulnerabilityThe Bluetooth handset of Mitel MiVoice 6873i, 6930, and 6940 SIP phones with firmware before 5.1.0.SP6 could allow an unauthenticated attacker within…EPSS 0.52%

Source: NIST National Vulnerability Database (record CVE-2022-29855), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.