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CVE-2018-10561

From Exploited flaws, HARD’s guide to the flaws being used in attacks · Checked
This article is about a flaw in Dasan Gigabit Passive Optical Network (GPON) Routers. For every flaw being used in attacks, see Exploited flaws.

CVE-2018-10561 is a security flaw in Dasan Gigabit Passive Optical Network (GPON) Routers. Attackers can run their own code on Dasan Gigabit Passive Optical Network (GPON) Routers. The US Cybersecurity and Infrastructure Security Agency (CISA) added it to its catalog of flaws known to be used in attacks on 31 Mar 2022.[1]

Dasan Gigabit Passive Optical Network (GPON) Routers is business software or equipment. Most families won’t have it, but attackers break into it to get inside companies, and from there to what those companies hold about their customers, patients and staff.

Description

CISA calls it a GPON routers authentication bypass in Dasan Gigabit Passive Optical Network (GPON) Routers. In its words: “Dasan GPON Routers contain an authentication bypass vulnerability. When combined with CVE-2018-10562, exploitation can allow an attacker to perform remote code execution.”[1]

The CVE record adds: “An issue was discovered on Dasan GPON home routers. It is possible to bypass authentication simply by appending "?images" to any URL of the device that requires authentication, as demonstrated by the /menu.html?images/ or /GponForm/diag_FORM?images/ URI. One can then manage the device.”[2]

The underlying weakness is improper authentication (CWE-287), in MITRE’s list of common software weaknesses.

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. CISA names the product as Dasan Gigabit Passive Optical Network (GPON) Routers.

Most families won’t have Dasan Gigabit Passive Optical Network (GPON) Routers; it’s for whoever looks after IT at work.

Exploitation

CISA added it to its catalog of known exploited vulnerabilities on 31 Mar 2022, 1,427 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 21 Apr 2022 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 93%. That’s in the top 1% of the flaws it scores.[3]

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

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

Fix

CISA’s required action: “The impacted product is end-of-life and should be disconnected if still in use.”[1]

  1. Check whether you use it.Dasan Gigabit Passive Optical Network (GPON) Routers is business software or equipment, so most families won’t have it. If you run a business, or work from home on company equipment, ask whoever looks after your IT.
  2. Send this page to your IT person.Ask them to confirm it’s fixed, or not in use. CISA gave US government agencies until 21 Apr 2022 to fix it.
  3. If it can’t be fixed, take it offline.CISA’s advice when there’s no fix is to stop using the product, or take it off the internet, until there is one.

You can’t fix someone else’s server, but you can watch for what follows a break-in like this: a breach notice, a password reset you didn’t ask for, or a scam message that knows things it shouldn’t. HARD watches for those for you and your family.

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 93%.[3]

See also

Other Dasan Gigabit Passive Optical Network (GPON) Routers flaws

Other improper authentication flaws

Added the same day

  • CVE-2022-26871, Trend Micro Apex Central: arbitrary file upload ·
  • CVE-2022-1040, Sophos Firewall: authentication bypass ·
  • CVE-2021-34484, Microsoft Windows: user profile service privilege escalation ·
  • CVE-2021-28799, QNAP Network Attached Storage (NAS): NAS improper authorization ·
  • CVE-2021-21551, Dell dbutil Driver: insufficient access control ·

References

  1. ^ Cybersecurity and Infrastructure Security Agency. “Dasan GPON Routers Authentication Bypass Vulnerability”. Known Exploited Vulnerabilities Catalog, added 31 Mar 2022.
  2. ^ National Institute of Standards and Technology. “CVE-2018-10561 Detail”. National Vulnerability Database, published 4 May 2018.
  3. ^ FIRST. “Exploit Prediction Scoring System”. EPSS 0.928, percentile 99.8, 31 Oct 2026.
  4. CVE Program. “CVE-2018-10561”. 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.