CVE-2019-12789 — An issue was discovered on Actiontec T2200H T2200H-31

An issue was discovered on Actiontec T2200H T2200H-31.128L.08 devices, as distributed by Telus. By attaching a UART adapter to the UART pins on the system board, an attacker can use a special key sequence (Ctrl-\) to obtain a shell with root privileges. After gaining root access,

01What is this vulnerability?

An issue was discovered on Actiontec T2200H T2200H-31.128L.08 devices, as distributed by Telus. By attaching a UART adapter to the UART pins on the system board, an attacker can use a special key sequence (Ctrl-\) to obtain a shell with root privileges. After gaining root access, the attacker can mount the filesystem read-write and make permanent modifications to the device including bricking of…

02Affected products

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

03Active exploitation status

Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.

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

Ask SARA in chat to draft a starting detection for this CVE in your stack of choice.

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: 2019-06-17T16:19:57.000Z
• Last modified: 2024-08-04T23:32:55.167Z

09References

• www.actiontec.com — https://www.actiontec.com/blog/
• seclists.org — http://seclists.org/fulldisclosure/2019/Jun/10