CVE-2019-17652 — A stack buffer overflow vulnerability in FortiClient for Linux 6

A stack buffer overflow vulnerability in FortiClient for Linux 6.2.1 and below may allow a user with low privilege to cause FortiClient processes running under root priviledge crashes via sending specially crafted "StartAvCustomScan" type IPC client requests to the fcts

01What is this vulnerability?

A stack buffer overflow vulnerability in FortiClient for Linux 6.2.1 and below may allow a user with low privilege to cause FortiClient processes running under root priviledge crashes via sending specially crafted "StartAvCustomScan" type IPC client requests to the fctsched process due the argv data not been well sanitized.

02Affected products

Vendor	Product	Versions
Fortinet	Fortinet FortiClientLinux	FortiClientLinux 6.2.1 and below

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: 2020-02-06T15:23:33.000Z
• Last modified: 2024-10-25T14:03:49.458Z

09References

• fortiguard.com — https://fortiguard.com/psirt/FG-IR-19-238
• danishcyberdefence.dk — https://danishcyberdefence.dk/blog/forticlient_linux