HOMEVULNERABILITIESCVE-2021-33600
HIGH

CVE-2021-33600

CWE-617Published: September 28, 2021· Updated: Jun 17, 2026

7.5
CVSS v3.1

Official Description

A denial-of-service (DoS) vulnerability was discovered in the web user interface of F-Secure Internet Gatekeeper. The vulnerability occurs because of an attacker can trigger assertion via malformed HTTP packet to web interface. An unauthenticated attacker could exploit this vulnerability by sending a large username parameter. A successful exploitation could lead to a denial-of-service of the product.

NVD Source

Technical Analysis

CVE-2021-33600 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in availability disruption (denial of service), with a CVSS base score of 7.5.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges Req.None
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityNone
IntegrityNone
AvailabilityHigh
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected Vendors & Products

f-secure1 product(s)
internet gatekeeper
Source: NVD CPE · 1 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

ADVISORYhttps://www.f-secure.com/en/business/programs/vulnerability-reward-program/hall-of-fame
ADVISORYhttps://www.f-secure.com/en/business/support-and-downloads/security-advisories/cve-2021-33600
ADVISORYhttps://www.f-secure.com/en/business/programs/vulnerability-reward-program/hall-of-fame
ADVISORYhttps://www.f-secure.com/en/business/support-and-downloads/security-advisories/cve-2021-33600

All References (4)

→
https://www.f-secure.com/en/business/programs/vulnerability-reward-program/hall-of-fameVendor Advisory
→
https://www.f-secure.com/en/business/support-and-downloads/security-advisories/cve-2021-33600Vendor Advisory
→
https://www.f-secure.com/en/business/programs/vulnerability-reward-program/hall-of-fameVendor Advisory
→
https://www.f-secure.com/en/business/support-and-downloads/security-advisories/cve-2021-33600Vendor Advisory

Quick Facts

CVE IDCVE-2021-33600
CVSS Score7.5 / 10
SeverityHIGH
WeaknessCWE-617
CISA KEVNo
Affected1 vendor(s)
PublishedSep 28, 2021

Related CVEs (CWE-617)

CVE-2019-9795
9.8
CVE-2020-3615
9.8
CVE-2020-12417
8.8
CVE-2020-6617
8.8
CVE-2020-6619
8.8
CVE-2020-6623
8.8

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2021-33600 in threat intel feeds
  • →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.
← All Vulnerabilities·Search for CVE-2021-33600·NVD