CVE-2020-17467

An issue was discovered in FNET through 4.6.4. The code for processing the hostname from an LLMNR request doesn't check for '\0' termination. Therefore, the deduced length of the hostname doesn't reflect the correct length of the actual data. This may lead to Information Disclosure in _fnet_llmnr_poll in fnet_llmnr.c during a response to a malicious request of the DNS class IN.

Published: 2020-12-11 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2020-17467 is rated High Risk (68.4/100): CVSS Critical severity, with medium exploitation likelihood (EPSS 3.04%). EPSS rose +2.01% over the last day, indicating growing attacker interest. High exploitation likelihood—assess exposure and prioritize remediation.

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

Exploit prediction scoring system (EPSS) score for CVE-2020-17467

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 2026-06-15 1.03% 3.04% +2.01%
2 2025-12-13 0.76% 1.03% +0.27%
3 2025-03-30 — 0.76% —

Full EPSS history (14 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2020-17467

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
9.1 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/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:H)
Serious risk that confidential data gets exposed in a big 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 5.2 [email protected]
6.4 2.0 MEDIUM
AV:N/AC:L/Au:N/C:P/I:N/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:P)
Partial availability impact.
 10.0 4.9 [email protected]

Weakness enumeration for CVE-2020-17467

Affected software / configurations for CVE-2020-17467

Vendor Product Version Raw CPE
butok fnet <= 4.6.4 cpe:2.3:a:butok:fnet:*:*:*:*:*:*:*:*

References for CVE-2020-17467

URL Tags
http://fnet.sourceforge.net/manual/fnet_history.html Release Notes Third Party Advisory
https://us-cert.cisa.gov/ics/advisories/icsa-20-343-01 Third Party Advisory US Government Resource
https://www.kb.cert.org/vuls/id/815128 Third Party Advisory US Government Resource
cvelogic Threat Intelligence