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CVE-2016-20017

From Exploited flaws, HARD’s guide to the flaws being used in attacks · Checked
This article is about a flaw in D-Link DSL-2750B Devices. For every flaw being used in attacks, see Exploited flaws; for D-Link’s, see D-Link flaws being used in attacks.

CVE-2016-20017 is a security flaw in D-Link DSL-2750B Devices, routers for homes and small offices. Attackers can run commands on D-Link DSL-2750B Devices from anywhere, without logging in. The US Cybersecurity and Infrastructure Security Agency (CISA) added it to its catalog of flaws known to be used in attacks on 8 Jan 2024.[1]

D-Link DSL-2750B Devices is in things households have: home and small-office routers, so the fix matters at home as much as at work. D-Link has published a fix or advice.

Description

CISA calls it a command injection in D-Link DSL-2750B Devices. In its words: “D-Link DSL-2750B devices contain a command injection vulnerability that allows remote, unauthenticated command injection via the login.cgi cli parameter.”[1]

The underlying weakness is command injection (CWE-77), in MITRE’s list of common software weaknesses.[2]

It scores 9.8 out of 10 on the Common Vulnerability Scoring System, which rates it critical, scored by NVD using CVSS 3.1.[2]

Affected versions

NVD’s record doesn’t list version ranges for it; D-Link’s advisory has them[3]. CISA names the product as D-Link DSL-2750B Devices.

Every device with D-Link DSL-2750B Devices needs the update.

Exploitation

CISA added it to its catalog of known exploited vulnerabilities on 8 Jan 2024, 446 days after it was made public. CISA lists a flaw only when it has reliable evidence of it being exploited, and gave US federal agencies until 29 Jan 2024 to fix it.[1]

FIRST’s Exploit Prediction Scoring System, which estimates how likely a flaw is to be used in attacks in the next 30 days from what it sees across the internet, puts it at 66%. That’s in the top 1% of the flaws it scores.[4]

CISA assesses it as automatable: attackers can run it against many targets at once.

CISA doesn’t say who was attacked, or how.

Fix

D-Link has published a fix or advice.[3] CISA’s required action: “Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.”[1]

  1. Update D-Link DSL-2750B Devices now.Open the router’s app, or its admin page in a browser, and look for a firmware update. Then turn on automatic updates, so the next fix arrives on its own.
  2. If the maker has stopped updating it, replace it.Routers stop getting fixes after a few years, and attackers keep a list of the ones that did. If there’s no newer firmware, it won’t be fixed.

Timeline

DateEvent
The flaw is made public in the National Vulnerability Database, with a severity score of 9.8.[2]
CISA adds it to its catalog of flaws known to be used in attacks.[1]
CISA’s deadline for US government agencies to fix it.[1]
FIRST puts the odds of it being used in attacks in the next 30 days at 66%.[4]

See also

Other D-Link flaws

  • CVE-2025-29635, D-Link DIR-823X: command injection ·
  • CVE-2022-37055, D-Link Routers: buffer overflow ·
  • CVE-2022-40799, D-Link DNR-322L: download of code without integrity check ·
  • CVE-2020-25079, D-Link DCS-2530L and DCS-2670L Devices: DCS-2530L and DCS-2670L command injection ·
  • CVE-2020-25078, D-Link DCS-2530L and DCS-2670L Devices: unspecified ·

Other command injection flaws

Added the same day

  • CVE-2023-41990, Apple devices: code execution ·
  • CVE-2023-38203, Adobe ColdFusion: deserialization of untrusted data ·
  • CVE-2023-29300, Adobe ColdFusion: deserialization of untrusted data ·
  • CVE-2023-27524, Apache Superset: insecure default initialization of resource ·
  • CVE-2023-23752, Joomla!: improper access control ·

Every D-Link flaw on CISA’s list · Everything added in January 2024

References

  1. ^ Cybersecurity and Infrastructure Security Agency. “D-Link DSL-2750B Devices Command Injection Vulnerability”. Known Exploited Vulnerabilities Catalog, added 8 Jan 2024.
  2. ^ National Institute of Standards and Technology. “CVE-2016-20017 Detail”. National Vulnerability Database, published 19 Oct 2022.
  3. ^ D-Link. Advisories and fixes: supportannouncement.us.dlink.com.
  4. ^ FIRST. “Exploit Prediction Scoring System”. EPSS 0.658, percentile 99.3, 31 Oct 2026.
  5. CVE Program. “CVE-2016-20017”. The official CVE record.

This article is built from CISA’s catalog (version 2026.10.30), NVD’s record and FIRST’s scores, kept in HARD’s database and checked every morning. The plain English is HARD’s.