CVE-2020-36178

Name: CVE-2020-36178
Creator: NVD / NIST
Published: 2021-01-06T21:15:14.317+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.8/10EPSS 9.70%

Last modified Jun 17, 2026

CVE-2020-36178 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. oal_ipt_addBridgeIsolationRules on TP-Link TL-WR840N 6_EU_0.9.1_4.16 devices allows OS command injection because a raw string entered from the web interface (an IP address field) is used directly for a call to the system library function (for iptables). NOTE: oal_ipt_addBridgeIsolationRules is not the only function that calls util_execSystem.. EPSS estimates a 9.70% chance of exploitation in the next 30 days.

Description

oal_ipt_addBridgeIsolationRules on TP-Link TL-WR840N 6_EU_0.9.1_4.16 devices allows OS command injection because a raw string entered from the web interface (an IP address field) is used directly for a call to the system library function (for iptables). NOTE: oal_ipt_addBridgeIsolationRules is not the only function that calls util_execSystem.

Metrics

CVSS 3.1

9.8/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS Probability

9.70%

94.9th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-78

Affected Software

Vendor	Product	Versions
Tp-Link	Tl-Wr840n Firmware	6_eu_0.9.1_4.16

References

https://github.com/therealunicornsecurity/therealunicornsecurity.github.io/blob/master/_posts/2020-10-11-TPLink.mdExploit, Third Party Advisory
https://therealunicornsecurity.github.io/TPLink/Exploit, Third Party Advisory
https://www.tp-link.com/fr/support/download/tl-wr840n/v6/#FirmwareVendor Advisory
https://github.com/therealunicornsecurity/therealunicornsecurity.github.io/blob/master/_posts/2020-10-11-TPLink.mdExploit, Third Party Advisory
https://therealunicornsecurity.github.io/TPLink/Exploit, Third Party Advisory
https://www.tp-link.com/fr/support/download/tl-wr840n/v6/#FirmwareVendor Advisory

Timeline

Published: Jan 6, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2020-36178?

How severe is CVE-2020-36178?

CVE-2020-36178 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 9.70% probability of exploitation in the next 30 days.

How do I fix CVE-2020-36178?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2020-36178?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST