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CVE-2018-19410

From Exploited flaws, HARD’s guide to the flaws being used in attacks · Checked
This article is about a flaw in Paessler PRTG Network Monitor. For every flaw being used in attacks, see Exploited flaws.

CVE-2018-19410 is a security flaw in Paessler PRTG Network Monitor. Attackers can read files on Paessler PRTG Network Monitor that should be out of reach 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 4 Feb 2025.[1]

Paessler PRTG Network Monitor 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. Paessler has published a fix or advice.

Description

CISA calls it a local file inclusion in Paessler PRTG Network Monitor. In its words: “Paessler PRTG Network Monitor contains a local file inclusion vulnerability that allows a remote, unauthenticated attacker to create users with read-write privileges (including administrator).”[1]

The CVE record adds: “PRTG Network Monitor before 18.2.40.1683 allows remote unauthenticated attackers to create users with read-write privileges (including administrator). A remote unauthenticated user can craft an HTTP request and override attributes of the 'include' directive in /public/login.htm and perform a Local File Inclusion attack, by including /api/addusers and executing it. By providing the 'id' and 'users' parameters, an unauthenticated attacker can create a user with read-write privileges (including administrator).”[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; Paessler’s advisory has them[3]. CISA names the product as Paessler PRTG Network Monitor.

Most families won’t have Paessler PRTG Network Monitor; it’s for whoever looks after IT at work.

Exploitation

CISA added it to its catalog of known exploited vulnerabilities on 4 Feb 2025, 2,267 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 25 Feb 2025 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 98%. 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

Paessler 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. Check whether you use it.Paessler PRTG Network Monitor 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 25 Feb 2025 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 98%.[4]

See also

Other Paessler PRTG Network Monitor flaws

Similar flaws

  • CVE-2026-114625, Arista VeloCloud Orchestrator: SQL injection ·
  • CVE-2026-96655, Plex Media Server: server-side request forgery (SSRF) ·
  • CVE-2026-96652, Plex Media Server: server-side request forgery (SSRF) ·
  • CVE-2026-21589, Atlassian products: files or directories accessible to external parties ·
  • CVE-2026-93616, Check Point products: path traversal ·

Added the same day

  • CVE-2024-45195, Apache OFBiz: forced browsing ·
  • CVE-2024-29059, Microsoft .NET Framework: information disclosure ·
  • CVE-2018-9276, Paessler PRTG Network Monitor: OS command injection ·

References

  1. ^ Cybersecurity and Infrastructure Security Agency. “Paessler PRTG Network Monitor Local File Inclusion Vulnerability”. Known Exploited Vulnerabilities Catalog, added 4 Feb 2025.
  2. ^ National Institute of Standards and Technology. “CVE-2018-19410 Detail”. National Vulnerability Database, published 21 Nov 2018.
  3. ^ Paessler. Advisories and fixes: paessler.com.
  4. ^ FIRST. “Exploit Prediction Scoring System”. EPSS 0.979, percentile 99.9, 31 Oct 2026.
  5. CVE Program. “CVE-2018-19410”. 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.