Medium severity · published Mar 4, 2021
CVE-2021-22128
An improper access control vulnerability in FortiProxy SSL VPN portal 2.0.0, 1.2.9 and below versions may allow an authenticated, remote attacker to access internal service such…
4.3
CVSS
1%
EPSS
No
On KEV
Description
An improper access control vulnerability in FortiProxy SSL VPN portal 2.0.0, 1.2.9 and below versions may allow an authenticated, remote attacker to access internal service such as the ZebOS Shell on the FortiProxy appliance through the Quick Connection functionality.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
Low
Integrity
None
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)1.0% · higher than 64% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
FO
Fortiproxy · Fortinet
through 1.2.9; 2.0.0 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-22128
CVE.org
https://www.cve.org/CVERecord?id=CVE-2021-22128
Vendor Advisory
https://fortiguard.com/advisory/FG-IR-20-235
More from Fortiproxy
9.8
CVE-2026-24858
Fortinet Multiple Products Authentication Bypass Using an Alternate Path or Channel Vulnerability
9.8
CVE-2025-59718
Fortinet Multiple Products Improper Verification of Cryptographic Signature Vulnerability
9.8
CVE-2024-55591
Fortinet FortiOS and FortiProxy Authentication Bypass Vulnerability
9.8
CVE-2024-23113
Fortinet Multiple Products Format String Vulnerability
9.8
CVE-2024-21762
Fortinet FortiOS Out-of-Bound Write Vulnerability