What is CVE-2018-20305?

CVE-2018-20305 is a critical-severity vulnerability in D-Link Dir-816 A2 Firmware, classified under Out-of-bounds Write. CVSS score: 9.8/10. Published 2018-12-20.

How severe is CVE-2018-20305?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Is CVE-2018-20305 known to be exploited?

1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Buffer overflow in D-Link Dir-816 A2 Firmware

CVE-2018-20305

D-Link DIR-816 A2 1.10 B05 devices allow arbitrary remote code execution without authentication via the newpass parameter. In the /goform/form2userconfig.cgi handler function, a long password may lead to a stack-based buffer overflow and overwrite a return address.

Vulnerability class: Buffer Overflow

Published 2018-12-20 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.041 (90.3th percentile), scored 2026-09-29.

Low probability of exploitation in the next 30 days, but still tracked. 90th percentile — 90.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.041 · newest: 0.041 · change: 0.000

Affected products

D-Link Dir-816 A2 Firmware — versions 1.10b05
Dlink Dir-816 A2

Weakness classification (CWE)

CWE-787 — Out-of-bounds Write

Public proof-of-concept exploits

ARPSyndicate/cve-scores

References

github.com/RootSoull/Vuln-Poc/tree/master/D-Link/DIR-816 (Exploit, Third Party Advisory)

Frequently asked questions

What is CVE-2018-20305?: CVE-2018-20305 is a critical-severity vulnerability in D-Link Dir-816 A2 Firmware, classified under Out-of-bounds Write. CVSS score: 9.8/10. Published 2018-12-20.
How severe is CVE-2018-20305?: Critical severity. CVSS v3 base score is 9.8 out of 10.
Is CVE-2018-20305 known to be exploited?: 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.