CVE-2021-20134

HIGH
8.4
CVSS Score
Published: December 30, 2021 at 09:31 PM UTC
Updated: June 17, 2026 at 03:33 AM UTC
3 products affected across 2 vendorsDir 2640-us FirmwareDir-2640-UsDir 2640-us

Using Quagga Services on D-Link DIR-2640 Routers by N/A?

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Severity
HIGH8.4
Exploit prediction
EPSS 8%

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v ≤ 1.11b02
dlink-dir-2640-us (same device)
v ≤ 1.11B02
All versions

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

References (1)

x_refsource_MISCExploitThird Party Advisory
https://www.tenable.com/security/research/tra-2021-44

CVSS

Attack Vector
ADJACENT_NETWORK
Complexity
LOW
Privileges
HIGH
User Interaction
NONE
Scope
CHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-22

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