CVE-2021-30047

Exp

VSFTPD 3.0.3 allows attackers to cause a denial of service due to limited number of connections allowed.

Published: 2023-08-22 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-30047 is rated High Exploit Risk (81.6/100): CVSS High severity, with high exploitation likelihood (EPSS 33.88%, 97th percentile). 1 public exploit reference(s) are indexed (Exploit-DB). EPSS rose +2.62% over the last day, indicating growing attacker interest. Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2021-30047

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2021-30047

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-17 31.26% 33.88% +2.62%
2 2026-03-04 32.63% 31.26% -1.37%
3 2026-03-01 — 32.63% —

Full EPSS history (42 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-30047

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 3.6 [email protected]

Weakness enumeration for CVE-2021-30047

OS Trackers for CVE-2021-30047

vendor priority summary link
redhat — — https://access.redhat.com/security/cve/CVE-2021-30047
ubuntu medium CVE-2021-30047 medium priority: Ubuntu including 1 source packages (vsftpd), 8 status rows across 8 suites (bionic, focal, jammy, lunar, mantic, trusty, upstream, xenial): not-affected 7, needs-triage 1. https://ubuntu.com/security/CVE-2021-30047

Affected software / configurations for CVE-2021-30047

Vendor Product Version Raw CPE
vsftpd_project vsftpd 3.0.3 cpe:2.3:a:vsftpd_project:vsftpd:3.0.3:*:*:*:*:*:*:*

References for CVE-2021-30047

URL Tags
https://www.exploit-db.com/exploits/49719 Exploit Third Party Advisory VDB Entry
cvelogic Threat Intelligence