CVE-2018-19986
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedIn the /HNAP1/SetRouterSettings message, the RemotePort parameter is vulnerable, and the vulnerability affects D-Link DIR-818LW Rev.A 2.05.B03 and DIR-822 B1 202KRb06 devices. In the SetRouterSettings.php source code, the RemotePort parameter is saved in the $path_inf_wan1."/web" internal configuration memory without any regex checking. And in the IPTWAN_build_command function of the iptwan.php source code, the data in $path_inf_wan1."/web" is used with the iptables command without any regex checking. A vulnerable /HNAP1/SetRouterSettings XML message could have shell metacharacters in the RemotePort element such as the `telnetd` string.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysisUser input reaches a shell or system command without being fully separated from the command itself, so an attacker can append their own instructions. Because these run with the application's privileges, it often means full control of the host. The lasting fix is to avoid the shell entirely — call APIs directly and pass arguments as data, never as concatenated strings.
General guidance for the os command injection class — the official description and references above are authoritative for this specific CVE. Want a bespoke review and a reviewed fix? Ask our team →
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data= 2.05.b03= 202krb06CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scopedLatest firmware from D-Link support for DIR-818LW Rev.A or DIR-822 B1 (verify version > 2.05.B03 and > 202KRb06 respectively)
- Identify the exact hardware revision of your D-Link device (label on the device shows model and hardware revision)
- Visit D-Link support site (support.dlink.com) and search for your device model
- Locate firmware downloads section and check for versions released AFTER the affected version (2.05.B03 for DIR-818LW, 202KRb06 for DIR-822)
- Download the latest available firmware for your specific hardware revision
- Follow D-Link's firmware upgrade instructions - typically involves accessing the web management interface, going to Tools > System, and using the firmware upgrade function
- After upgrade, verify the RemotePort parameter in /HNAP1/SetRouterSettings no longer accepts shell metacharacters
- If no firmware update is available from D-Link, consider replacing the device as these older DIR-818LW and DIR-822 models may be end-of-life
Generated from the published advisory — verify against the referenced sources before acting.
There is no version to upgrade to and no patch to apply. Every affected install stays exposed until the vendor ships a fix — or somebody else builds one.
Free. We build fixes in the order the community asks for them — and we’ll tell you the moment this one lands.
We develop and verify an original fix where the vendor hasn’t, from $3,550. Deployed to your staging first — never straight to production.
Scope it with usSee what else the community needs solved on the solutions-needed board.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2018-19986 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2018-19986 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.
A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data