CVE-2019-14657 — Yealink phones through 2019-08-04 have an issue with OpenVPN file upload

Yealink phones through 2019-08-04 have an issue with OpenVPN file upload. They execute tar as root to extract files, but do not validate the extraction directory. Creating a tar file with ../../../../ allows replacement of almost any file on a phone. This leads to password replac

01What is this vulnerability?

Yealink phones through 2019-08-04 have an issue with OpenVPN file upload. They execute tar as root to extract files, but do not validate the extraction directory. Creating a tar file with ../../../../ allows replacement of almost any file on a phone. This leads to password replacement and arbitrary code execution as root.

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: 2019-10-08T12:02:34.000Z
• Last modified: 2024-08-05T00:19:41.434Z

09References

• cerebusforensics.com — http://cerebusforensics.com/yealink/exploit.html
• sway.office.com — https://sway.office.com/3pCb559LYVuT0eig