CVE-2022-26143 — MiCollab, MiVoice Business Express Access Control Vulnerability

The TP-240 (aka tp240dvr) component in Mitel MiCollab before 9.4 SP1 FP1 and MiVoice Business Express through 8.1 allows remote attackers to obtain sensitive information and cause a denial of service (performance degradation and excessive outbound traffic). This was exploited in

01What is this vulnerability?

The TP-240 (aka tp240dvr) component in Mitel MiCollab before 9.4 SP1 FP1 and MiVoice Business Express through 8.1 allows remote attackers to obtain sensitive information and cause a denial of service (performance degradation and excessive outbound traffic). This was exploited in the wild in February and March 2022 for the TP240PhoneHome DDoS attack.

02Affected products

Vendor	Product	Versions
n	a / n/a	n/a

03Active exploitation status

Yes — actively exploited. Added to the CISA KEV catalog on 2022-03-25. Ransomware use: Unknown.

04Recommended remediation

• Patch to a fixed version listed in the vendor advisory (see references below).
• Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
• Hunt historical logs for exploitation indicators — see Detection signatures below.

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Open the Sigma generator with a pre-filled prompt for this CVE to draft a starting detection in your stack of choice:

Open in Sigma generator →

07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

• Published: 2022-03-09T15:32:54.000Z
• Last modified: 2025-10-21T23:15:44.508Z
• Added to CISA KEV: 2022-03-25
• BOD 22-01 due: 2022-04-15

09References

• www.mitel.com — https://www.mitel.com/en-ca/support/security-advisories/mitel-product-security-a…
• www.akamai.com — https://www.akamai.com/blog/security/phone-home-ddos-attack-vector
• www.shadowserver.org — https://www.shadowserver.org/news/cve-2022-26143-tp240phonehome-reflection-ampli…
• news.ycombinator.com — https://news.ycombinator.com/item?id=30614073
• blog.cloudflare.com — https://blog.cloudflare.com/cve-2022-26143/
• team-cymru.com — https://team-cymru.com/blog/2022/03/08/record-breaking-ddos-potential-discovered…
• arstechnica.com — https://arstechnica.com/information-technology/2022/03/ddosers-use-new-method-ca…