No exploitation reportedFix available

CVE-2021-3554

Q: Is CVE-2021-3554 actively exploited?

Active exploitation of CVE-2021-3554 has not been confirmed. Its EPSS score was 2.1% on 2026-10-23, the estimated probability of exploitation in the next 30 days.

Q: What is the CVSS score for CVE-2021-3554?

CVE-2021-3554 has a CVSS v3 base score of 10 (CRITICAL severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H.

No exploitation reported by the sources we read.

Published2021-11-24
Fixed in7.1.2.33 · 6.6.27.390
WeaknessCWE-284

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

Improper Access Control vulnerability in the patchesUpdate API as implemented in Bitdefender Endpoint Security Tools for Linux as a relay role allows an attacker to manipulate the remote address used for pulling patches. This issue affects: Bitdefender Endpoint Security Tools for Linux versions prior to 6.6.27.390; versions prior to 7.1.2.33. Bitdefender Unified Endpoint versions prior to 6.2.21.160. Bitdefender GravityZone versions prior to 6.24.1-1.

Timeline

dates in UTC

2021-11-2416:15CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-10-23 21:37 UTC

Indicators tagged with this CVE, per day0 indicators over 7 days

Block these indicators

Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2021-3554?format=txt
CSV export: https://api.ismalicious.com/edl/cve/CVE-2021-3554?format=csv
TAXII collection of exploited CVEs
The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD

Bitdefender endpoint security tools

Branch	Affected	Fixed in	Source
7.x	≥ 7.0.0.00, < 7.1.2.33	7.1.2.33	NVD
6.6	< 6.6.27.390	6.6.27.390	NVD

Bitdefender gravityzone

Branch	Affected	Fixed in	Source
6.24	< 6.24.1-1	6.24.1-1	NVD
6.24	= 6.24.1-1	no fix published	NVD

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Fix

Update Bitdefender endpoint security tools to 7.1.2.33 · 6.6.27.390

Detection

Nuclei template: none so far
Exploit-DB: no entry
Proof-of-concept repositories: none listed

Sources

CNACVSS 3.19read 2026-10-23
NVDCVSS 3.110read 2026-10-23
NVDCVSS 2.07.5read 2026-10-23
CNAweakness (CWE)CWE-284read 2026-10-23
FIRST EPSSEPSS score2.1 %2026-10-23

Technical details

CVSS v3 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
Published: 2021-11-24
Last Modified: 2026-06-17
NVD status: Modified

Frequently asked questions

What is CVE-2021-3554?

Is CVE-2021-3554 actively exploited?

Active exploitation of CVE-2021-3554 has not been confirmed. Its EPSS score was 2.1% on 2026-10-23, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2021-3554?

CVE-2021-3554 has a CVSS v3 base score of 10 (CRITICAL severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H.

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