CVE-2020-24363
CVE-2020-24363 is a security flaw in TP-Link TL-WA855RE, routers for homes and small offices. Attackers can get into TP-Link TL-WA855RE without a valid password. The US Cybersecurity and Infrastructure Security Agency (CISA) added it to its catalog of flaws known to be used in attacks on 2 Sep 2025.[1]
TP-Link TL-WA855RE is in things households have: home and small-office routers, so the fix matters at home as much as at work. TP-Link has published a fix or advice.
Description
CISA calls it a missing authentication for critical function in TP-Link TL-WA855RE. In its words: “TP-link TL-WA855RE contains a missing authentication for critical function vulnerability. This vulnerability could allow an unauthenticated attacker (on the same network) to submit a TDDP_RESET POST request for a factory reset and reboot. The attacker can then obtain incorrect access control by setting a new administrative password. The impacted products could be end-of-life (EoL) and/or end-of-service (EoS). Users should discontinue product utilization.”[1]
The underlying weakness is missing authentication (CWE-306), in MITRE’s list of common software weaknesses.[2]
It scores 8.8 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; TP-Link’s advisory has them[3]. CISA names the product as TP-Link TL-WA855RE.
Every device with TP-Link TL-WA855RE needs the update.
Exploitation
CISA added it to its catalog of known exploited vulnerabilities on 2 Sep 2025, 1,828 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 23 Sep 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 22%. That’s in the top 3% 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
TP-Link has published a fix or advice.[3] CISA’s required action: “Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.”[1]
- Update TP-Link TL-WA855RE 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 8.8.[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 22%.[4] |
See also
Other TP-Link flaws
- CVE-2025-9377, TP-Link Multiple Routers: archer C7(EU) and TL-WR841N/ND(MS) OS command injection ·
- CVE-2023-50224, TP-Link TL-WR841N: authentication bypass by spoofing ·
- CVE-2023-33538, TP-Link Multiple Routers: command injection ·
- CVE-2023-1389, TP-Link Archer AX21: archer AX-21 command injection ·
- CVE-2015-3035, TP-Link Multiple Archer Devices: directory traversal ·
Other missing authentication flaws
- CVE-2026-111357, Ivanti Connect Secure: missing authentication for critical function ·
- CVE-2026-67277, MikroTik RouterOS: missing authentication for critical function ·
- CVE-2026-81578, PaperCut NG/MF: missing authentication for critical function ·
- CVE-2026-72529, TrueConf Server: missing authentication for critical function ·
- CVE-2026-56164, Microsoft SharePoint Server: missing authentication for critical function ·
Added the same day
- CVE-2025-55177, Meta Platforms WhatsApp: incorrect authorization ·
Every TP-Link flaw on CISA’s list · Everything added in September 2025
References
- ^ Cybersecurity and Infrastructure Security Agency. “TP-link TL-WA855RE Missing Authentication for Critical Function Vulnerability”. Known Exploited Vulnerabilities Catalog, added 2 Sep 2025.
- ^ National Institute of Standards and Technology. “CVE-2020-24363 Detail”. National Vulnerability Database, published 31 Aug 2020.
- ^ TP-Link. Advisories and fixes: tp-link.com, tp-link.com.
- ^ FIRST. “Exploit Prediction Scoring System”. EPSS 0.222, percentile 97.7, 31 Oct 2026.
- CVE Program. “CVE-2020-24363”. 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.