An issue was discovered in Forescout CounterACT before 8.1.4.

published 2021-04-14 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-14802

cvss: 7.8; version 3.1, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 0.4%; EPSS 0.4% chance of exploitation in 30 days, percentile 36%
public exploits: 0; none known

An issue was discovered in Forescout CounterACT before 8.1.4. A local privilege escalation vulnerability is present in the logging function. SecureConnector runs with administrative privileges and writes logs entries to a file in %PROGRAMDATA%\ForeScout SecureConnector\ that has full permissions for the Everyone group. Using a symbolic link allows an attacker to point the log file to a privileged location such as %WINDIR%\System32. The resulting log file adopts the file permissions of the source of the symbolic link (in this case, the Everyone group). The log file in System32 can be replaced and renamed with a malicious DLL for DLL hijacking.

Patch / fix

fixed in 1

forescout counteract 8.1.4

Exploit prediction

0.42% chance of exploitation in the next 30 days, higher than 36% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

adversis.io https://www.adversis.io/research/2021/3/30/forescout-secure-connector-local-privilege-escalation referenced PoC, tagged "exploit" by a source, unverified
jordanpotti.com https://jordanpotti.com/2021/03/30/forescout-priv-esc-folder-permissions/ referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
NVD	3.1	7.8	CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
NVD	2.0	4.4	AV:L/AC:M/Au:N/C:P/I:P/A:P

Classification

Weakness

CWE-59 Improper Link Resolution Before File Access
CWE-427 Uncontrolled Search Path Element
CWE-732 Incorrect Permission Assignment for Critical Resource

References

adversis.io /research/2021/3/30/forescout-secure-connector-local-privilege-escalation
exploit, third-party-advisory
jordanpotti.com /2021/03/30/forescout-priv-esc-folder-permissions/
exploit, third-party-advisory
docs.forescout.com
vendor-advisory

Sources

CVE List CVE-2021-28098
NVD CVE-2021-28098

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary