CVE-2018-14558
CVE-2018-14558 is a security flaw in Tenda AC7, AC9, and AC10 Routers, routers for homes and small offices. Attackers can run commands on Tenda AC7, AC9, and AC10 Routers. The US Cybersecurity and Infrastructure Security Agency (CISA) added it to its catalog of flaws known to be used in attacks on 3 Nov 2021.[1]
Tenda AC7, AC9, and AC10 Routers is in things households have: home and small-office routers, so the fix matters at home as much as at work.
Description
CISA calls it a command injection in Tenda AC7, AC9, and AC10 Routers. In its words: “Tenda AC7, AC9, and AC10 devices contain a command injection vulnerability due to the "formsetUsbUnload" function executes a dosystemCmd function with untrusted input. Successful exploitation allows an attacker to execute OS commands via a crafted goform/setUsbUnload request.”[1]
The CVE record adds: “An issue was discovered on Tenda AC7 devices with firmware through V15.03.06.44_CN(AC7), AC9 devices with firmware through V15.03.05.19(6318)_CN(AC9), and AC10 devices with firmware through V15.03.06.23_CN(AC10). A command Injection vulnerability allows attackers to execute arbitrary OS commands via a crafted goform/setUsbUnload request. This occurs because the "formsetUsbUnload" function executes a dosystemCmd function with untrusted input.”[2]
The underlying weakness is OS command injection (CWE-78), 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 Tenda AC7, AC9, and AC10 Routers.
Every device with Tenda AC7, AC9, and AC10 Routers needs the update.
Exploitation
CISA added it to its catalog of known exploited vulnerabilities on 3 Nov 2021, 1,100 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 3 May 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 9%. That’s in the top 5% 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: “Apply updates per vendor instructions.”[1]
- Update Tenda AC7, AC9, and AC10 Routers 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 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 9%.[3] |
See also
Other Tenda flaws
- CVE-2021-31755, Tenda AC11 Router: stack buffer overflow ·
- CVE-2020-10987, Tenda AC1900 Router AC15 Model: remote code execution ·
Other OS command injection flaws
- CVE-2026-110447, Collabora Online – Built-in CODE Server: online – built-in CODE server OS command injection ·
- CVE-2026-106931, EG Secure Solutions SiteGuard Server Edition: OS command injection ·
- CVE-2026-83549, SonicWall SMA1000 Appliances: OS command injection ·
- CVE-2026-49869, Kestra OSS: OSS OS command injection ·
- CVE-2026-73570, Synacor Zimbra Collaboration Suite (ZCS): OS command injection ·
Added the same day
- CVE-2021-42258, BQE BillQuick Web Suite: SQL injection ·
- CVE-2021-42013, Apache HTTP Server: path traversal ·
- CVE-2021-41773, Apache HTTP Server: path traversal ·
- CVE-2021-40539, Zoho ManageEngine: aDSelfService plus authentication bypass ·
- CVE-2021-40444, Microsoft MSHTML: remote code execution ·
Every Tenda flaw on CISA’s list · Everything added in November 2021
References
- ^ Cybersecurity and Infrastructure Security Agency. “Tenda AC7, AC9, and AC10 Routers Command Injection Vulnerability”. Known Exploited Vulnerabilities Catalog, added 3 Nov 2021.
- ^ National Institute of Standards and Technology. “CVE-2018-14558 Detail”. National Vulnerability Database, published 30 Oct 2018.
- ^ FIRST. “Exploit Prediction Scoring System”. EPSS 0.085, percentile 95.0, 31 Oct 2026.
- CVE Program. “CVE-2018-14558”. 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.