CVE-2021-20134
8.4 · HIGHOverview
CVE-2021-20134 is a high-severity vulnerability affecting dlink dir-2640-us_firmware. It was published on December 30, 2021 and has a CVSS 3.1 base score of 8.4 (HIGH).
This vulnerability has a CVSS 3.1 base score of 8.4, rated HIGH. It requires local or adjacent network access to exploit. Some level of privileges is required for exploitation.
Technical Description
Quagga Services on D-Link DIR-2640 less than or equal to version 1.11B02 are affected by an absolute path traversal vulnerability that allows a remote, authenticated attacker to set an arbitrary file on the router's filesystem as the log file used by either Quagga service (zebra or ripd). Subsequent log messages will be appended to the file, prefixed by a timestamp and some logging metadata. Remote code execution can be achieved by using this vulnerability to append to a shell script on the router's filesystem, and then awaiting or triggering the execution of that script. A remote, unauthenticated root shell can easily be obtained on the device in this fashion.
Remediation
Check the references section for vendor advisories and patches from dlink. Update dir-2640-us_firmware to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
Affected Products
| Vendor | Product | Versions | Status |
|---|---|---|---|
| dlink | dir-2640-us_firmware | 0 | Affected |
Frequently Asked Questions
What is CVE-2021-20134?
CVE-2021-20134 is a high-severity vulnerability affecting dlink dir-2640-us_firmware. It was published on December 30, 2021 and has a CVSS 3.1 base score of 8.4 (HIGH).
How severe is CVE-2021-20134?
This vulnerability has a CVSS 3.1 base score of 8.4, rated HIGH. It requires local or adjacent network access to exploit. Some level of privileges is required for exploitation.
How do I fix or remediate CVE-2021-20134?
Check the references section for vendor advisories and patches from dlink. Update dir-2640-us_firmware to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2021-20134?
CyberStrike's AI-powered security agents can automatically detect CVE-2021-20134 across your infrastructure using autonomous pentesting, DAST scanning, and HackBrowser. The platform continuously monitors for known vulnerabilities and provides actionable remediation guidance prioritized by real-world exploitability.
How CyberStrike Helps
AI agents map your attack surface to find vulnerabilities like this one.
Automated penetration testing that runs continuously, not just quarterly.
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Browser-based exploitation validates findings with real proof-of-concept.
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