CVE-2018-20305: D-Link DIR-816 A2 1.10 B05 devices allow arbitrary remote code execution without authentication via the newpas

This week

CRITICAL 9.8REMOTEMITIGATE

CVE-2018-20305 is a critical-severity flaw (CVSS 9.8) affecting dir-816 a2 firmware. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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.

Why this priority

Critical severity
EPSS top 9%: very likely to be exploited
Public exploit reference
Remotely exploitable, no login, no user action

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	9.8 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	4.1% (top 9%)
CISA exploited list	No
Weakness	CWE-787
Published	2018-12-20
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: d-link

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2018-12-20 00:29 UTCPublished CVE record published
2026-06-17 01:52 UTCUpdated Record last modified

d-link dir-816 a2 firmware MITIGATE

Affected: 1.10b05

Fixed in: no fixed release known

Safe to downgrade to: a release before 1.10b05

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2018-20305?

dir-816 a2 firmware: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2018-20305 being exploited?

CVE-2018-20305 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2018-20305 affect?

CVE-2018-20305 affects dir-816 a2 firmware. Severity is critical (CVSS 9.8). 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 ov

How urgent is CVE-2018-20305?

Priority 67/100. Critical severity; EPSS top 9%: very likely to be exploited; Public exploit reference; Remotely exploitable, no login, no user action

Software pages

D-Link vulnerabilities

Related CVEs

CVE-2025-44835 MEDIUM 6.3 MITIGATE D-Link DIR-816 A2V1.1.0B05 was found to contain a command injection in iptablesWebsFilterRun, which allows rem
CVE-2024-0921 MEDIUM 4.7 MITIGATE A vulnerability has been found in D-Link DIR-816 A2 1.10CNB04 and classified as critical
CVE-2023-43240 CRITICAL 9.8 MITIGATE D-Link DIR-816 A2 v1.10CNB05 was discovered to contain a stack overflow via parameter sip_address in ipportFil
CVE-2023-43239 CRITICAL 9.8 MITIGATE D-Link DIR-816 A2 v1.10CNB05 was discovered to contain a stack overflow via parameter flag_5G in showMACfilter
CVE-2023-43238 CRITICAL 9.8 MITIGATE D-Link DIR-816 A2 v1.10CNB05 was discovered to contain a stack overflow via parameter nvmacaddr in form2Dhcpip

References

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