CVE-2021-3641

System denial of service via symlink file overwrite

Published Nov 9, 2021 · Updated Sep 17, 2024

Link-following in the Endpoint Agent in Bitdefender GravityZone 7.1.2.33 and earlier allows local users to cause a system denial of service. The agent service follows an attacker-created symbolic link and overwrites the linked file instead of safely resolving or rejecting the path. Low-privileged code execution on the Windows endpoint is required, and the resulting file overwrite can interrupt the system.

CVSS severity6.1
Medium
EPSS probability0.35%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Link-following in the Endpoint Agent in Bitdefender GravityZone 7.1.2.33 and earlier allows local users to cause a system denial of service. The agent service follows an attacker-created symbolic link and overwrites the linked file instead of safely resolving or rejecting the path. Low-privileged code execution on the Windows endpoint is required, and the resulting file overwrite can interrupt the system.

The record

CVE
CVE-2021-3641
Published
Nov 9, 2021
Updated
Sep 17, 2024
Vendor
Bitdefender
Product
GravityZone
Classifications
CWE-59, T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Nov 9, 2021CVE publishedPublication date reported by the CVE source.
  2. Sep 17, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=unspecified <=7.1.2.33

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Bitdefender · GravityZoneversion=unspecified <=7.1.2.33

Published CVSS scores

6.1BitdefenderCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:H
3.6NVDAV:L/AC:L/Au:N/C:N/I:P/A:P

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-59Improper Link Resolution Before File Access ('Link Following')
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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