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Mallory
Medium

Authenticated command injection in NETGEAR mini_httpd funjsq_access_token

IdentifiersCVE-2020-27867CWE-78

CVE-2020-27867 is a command injection vulnerability affecting multiple NETGEAR router models, including R6020, R6080, R6120, R6220, R6260, R6700v2, R6800, R6900v2, R7450, JNR3210, WNR2020, Nighthawk AC2100, and Nighthawk AC2400. The flaw exists in the mini_httpd service exposed on TCP/80 by default. Specifically, when processing the funjsq_access_token parameter, the service fails to properly validate attacker-controlled input before passing it to a system call. Although exploitation is nominally authenticated, the product's authentication mechanism can be bypassed, allowing a network-adjacent attacker to reach the vulnerable code path and execute arbitrary commands. Successful exploitation results in arbitrary code execution as root on the device.

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For your environment

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ANALYST BRIEF

Impact, mitigation & remediation

What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.

Impact

What an attacker gets, and what they’ve been doing with it.

Successful exploitation allows arbitrary code execution in the root context on the affected router. This gives an attacker full control of the device, including the ability to modify configuration, install persistent malware, intercept or redirect traffic, pivot into adjacent networks, exfiltrate sensitive data, and disrupt router operation or availability.

Mitigation

If you can’t patch tonight, do this now.

Until patched, restrict access to the router's web management interface, especially from untrusted or adjacent networks. Disable remote administration if enabled, limit management access to trusted hosts or a dedicated management network, and use network controls to block access to TCP/80 on the device from non-administrative segments. Monitor for unexpected changes to router configuration and signs of compromise, and replace or reflash devices suspected of exploitation.

Remediation

Patch, then assume compromise.

Apply NETGEAR firmware updates that address CVE-2020-27867 for the affected router models. If vendor-fixed firmware is available, upgrade to the patched release for the specific hardware revision. Because the flaw is in the web management service and can lead to root-level compromise, remediation should be prioritized for any exposed or reachable devices.
PUBLIC EXPLOITS

Exploits

No public exploits tracked yet. Mallory keeps watching.

VALID 0 / 0 TOTALView more in app

No public exploit code observed for this vulnerability.

EXPOSURE SURFACE

Affected products & vendors

Products and vendors Mallory has correlated with this vulnerability. Open in Mallory to drill down to specific CPE configurations and version ranges.

VendorProductType
NetgearAc2100 Firmwareoperating_system
NetgearAc2400 Firmwareoperating_system
NetgearAc2600 Firmwareoperating_system
NetgearR6020 Firmwareoperating_system
NetgearR6080 Firmwareoperating_system
NetgearR6120 Firmwareoperating_system
NetgearR6220 Firmwareoperating_system
NetgearR6230 Firmwareoperating_system
NetgearR6260 Firmwareoperating_system
NetgearR6330 Firmwareoperating_system
NetgearR6350 Firmwareoperating_system
NetgearR6700 Firmwareoperating_system
NetgearR6800 Firmwareoperating_system
NetgearR6850 Firmwareoperating_system
NetgearR6900 Firmwareoperating_system
NetgearR7200 Firmwareoperating_system
NetgearR7350 Firmwareoperating_system
NetgearR7400 Firmwareoperating_system
NetgearR7450 Firmwareoperating_system

Vendor-confirmed product mapping. Mallory continuously reconciles this list against your asset inventory.

What this page doesn’t show

The version that knows your environment.

This page is what’s public. Mallory adds the parts that aren’t: which of your assets are affected, which adversaries are exploiting it right now, which detections to deploy, and what to do tonight.
Exposure mapping

Query your assets running an affected version, and investigate the blast radius.

Threat actor evidence1

Every observed campaign linking this CVE to a named adversary.

Associated malware1

Malware families riding this exploit, with evidence and IOCs.

Detection signatures

YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.

Vendor-by-vendor mapping

Cross-references every affected SKU, including bundled OEM variants.

Social activity2

Community discussion across Reddit, Mastodon, and other social sources.