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Fencer Vulns
critical 9.8

CVE-2020-36178 json

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…

published 2021-01-06 5 y ago modified 2026-06-17 4 mo ago also EUVD-2020-23756

cvss
9.8
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
9.8%
EPSS 9.8% chance of exploitation in 30 days, percentile 95%
public exploits
0
none known

Summary

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.

Exploit prediction

9.82% chance of exploitation in the next 30 days, higher than 95% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • therealunicornsecurity.github.io https://therealunicornsecurity.github.io/TPLink/ referenced PoC, tagged "exploit" by a source, unverified
  • github.com https://github.com/therealunicornsecurity/therealunicornsecurity.github.io/blob/master/_posts/2020-10-11-TPLink.md referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 10.0 AV:N/AC:L/Au:N/C:C/I:C/A:C

Classification

Weakness
  • CWE-78 Improper Neutralization of Special Elements used in an OS Command

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.