CVE-2020-36178Network attack vector

Unauthenticated command execution via unsanitized IP input

Published Jan 6, 2021 · Updated Aug 4, 2024

OS command injection in TP-Link TL-WR840N 6_EU_0.9.1_4.16 firmware allows remote attackers to execute commands through an IP field. oal_ipt_addBridgeIsolationRules inserts the raw field value into an iptables command passed through util_execSystem to system without sanitization. NVD rates the path unauthenticated with no user interaction, although the original analysis did not verify exploitation on a live device.

CVSS severity9.8
Critical
EPSS probability9.70%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

OS command injection in TP-Link TL-WR840N 6_EU_0.9.1_4.16 firmware allows remote attackers to execute commands through an IP field. oal_ipt_addBridgeIsolationRules inserts the raw field value into an iptables command passed through util_execSystem to system without sanitization. NVD rates the path unauthenticated with no user interaction, although the original analysis did not verify exploitation on a live device.

The record

CVE
CVE-2020-36178
Published
Jan 6, 2021
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-78, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 6, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

10.0NIST NVDAV:N/AC:L/Au:N/C:C/I:C/A:C
9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-78Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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