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Fencer Vulns
high 8.7

CVE-2020-36872 json

BACnet Test Server 1.01 Malformed BVLC Length DoS

published 2025-11-26 11 mo ago modified 2026-07-28 3 mo ago also EUVD-2020-30820

cvss
8.7
version 4.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 45%
public exploits
0
none known

Summary

BACnet Test Server versions up to and including 1.01 contains a remote denial of service vulnerability in its BACnet/IP BVLC packet handling. The server fails to properly validate the BVLC Length field in incoming UDP BVLC frames on the default BACnet port (47808/udp). A remote unauthenticated attacker can send a malformed BVLC Length value to trigger an access violation and crash the application, resulting in a denial of service.

CISA SSVC

Exploitation
Proof of concept is public
Automatable
yes
Technical impact
partial
Assessed
11 mo ago

Exploit prediction

0.53% chance of exploitation in the next 30 days, higher than 45% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • zeroscience.mk https://www.zeroscience.mk/en/vulnerabilities/ZSL-2020-5597.php referenced PoC, tagged "exploit" by a source, unverified
  • exploit-db.com https://www.exploit-db.com/exploits/48860 referenced PoC, tagged "exploit" by a source, unverified
  • packetstormsecurity.com https://packetstormsecurity.com/files/159504 referenced PoC, tagged "exploit" by a source, unverified
  • cxsecurity.com https://cxsecurity.com/issue/WLB-2020100045 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 4.0 8.7 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
CNA 4.0 8.7 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Affected products

  • BACnet Interoperability Test Services, Inc. BACnet Test Server

Classification

Weakness
  • CWE-400 Uncontrolled Resource Consumption

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.