CVE-2017-5521
CVE-2017-5521 is a security flaw in NETGEAR Multiple Devices, routers for homes and small offices. Attackers can read information from NETGEAR Multiple Devices that should be private. The US Cybersecurity and Infrastructure Security Agency (CISA) added it to its catalog of flaws known to be used in attacks on 8 Sep 2022.[1]
NETGEAR Multiple Devices is in things households have: home and small-office routers, so the fix matters at home as much as at work. NETGEAR has published a fix or advice.
Description
CISA calls it an exposure of sensitive information in NETGEAR Multiple Devices. In its words: “Multiple NETGEAR devices are prone to admin password disclosure via simple crafted requests to the web management server.”[1]
The CVE record adds: “An issue was discovered on NETGEAR R8500, R8300, R7000, R6400, R7300, R7100LG, R6300v2, WNDR3400v3, WNR3500Lv2, R6250, R6700, R6900, and R8000 devices. They are prone to password disclosure via simple crafted requests to the web management server. The bug is exploitable remotely if the remote management option is set, and can also be exploited given access to the router over LAN or WLAN. When trying to access the web panel, a user is asked to authenticate; if the authentication is canceled and password recovery is not enabled, the user is redirected to a page that exposes a password recovery token. If a user supplies the correct token to the page /passwordrecovered.cgi?id=TOKEN (and password recovery is not enabled), they will receive the admin password for the router. If password recovery is set the exploit will fail, as it will ask the user for the recovery…”[2]
The underlying weakness is information exposure (CWE-200), in MITRE’s list of common software weaknesses.
It scores 8.1 out of 10 on the Common Vulnerability Scoring System, which rates it high, scored by NVD using CVSS 3.1.[2]
Affected versions
NVD’s record doesn’t list version ranges for it; NETGEAR’s advisory has them[3]. CISA names the product as NETGEAR Multiple Devices.
Every device with NETGEAR Multiple Devices needs the update.
Exploitation
CISA added it to its catalog of known exploited vulnerabilities on 8 Sep 2022, 2,060 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 Sep 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 89%. That’s in the top 1% of the flaws it scores.[4]
CISA assesses it as not automatable: each attack takes some work.
CISA doesn’t say who was attacked, or how.
Fix
NETGEAR has published a fix or advice.[3] CISA’s required action: “Apply updates per vendor instructions.”[1]
- Update NETGEAR Multiple 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.
- 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
| Date | Event |
|---|---|
| The flaw is made public in the National Vulnerability Database, with a severity score of 8.1.[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 89%.[4] |
See also
Other NETGEAR Multiple Devices flaws
- CVE-2017-6862: buffer overflow ·
Other NETGEAR flaws
- CVE-2017-6334, NETGEAR DGN2200 Devices: OS command injection ·
- CVE-2016-1555, NETGEAR Wireless Access Point (WAP) Devices: multiple WAP devices command injection ·
- CVE-2016-10174, NETGEAR WNR2000v5 Router: buffer overflow ·
- CVE-2017-6077, NETGEAR Wireless Router DGN2200: dGN2200 remote code execution ·
- CVE-2016-6277, NETGEAR Multiple Routers: remote code execution ·
Other information exposure flaws
- CVE-2025-68686, Fortinet FortiOS: exposure of sensitive information to an unauthorized actor ·
- CVE-2026-20133, Cisco Catalyst SD-WAN Manager: exposure of sensitive information to an unauthorized actor ·
- CVE-2025-31125, Vitejs: improper access control ·
- CVE-2026-20805, Microsoft Windows: information disclosure ·
- CVE-2021-41277, Metabase: geoJSON API local file inclusion ·
Added the same day
- CVE-2022-3075, Chrome and other Chromium browsers: insufficient data validation ·
- CVE-2022-27593, QNAP Photo Station: externally controlled reference ·
- CVE-2022-26258, D-Link DIR-820L: remote code execution ·
- CVE-2020-9934, Apple iOS, iPadOS, and macOS: input validation ·
- CVE-2018-7445, MikroTik RouterOS: stack-based buffer overflow ·
Every NETGEAR flaw on CISA’s list · Everything added in September 2022
References
- ^ Cybersecurity and Infrastructure Security Agency. “NETGEAR Multiple Devices Exposure of Sensitive Information Vulnerability”. Known Exploited Vulnerabilities Catalog, added 8 Sep 2022.
- ^ National Institute of Standards and Technology. “CVE-2017-5521 Detail”. National Vulnerability Database, published 17 Jan 2017.
- ^ NETGEAR. Advisories and fixes: kb.netgear.com.
- ^ FIRST. “Exploit Prediction Scoring System”. EPSS 0.894, percentile 99.8, 31 Oct 2026.
- CVE Program. “CVE-2017-5521”. 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.