CVE-2021-20134

highpriority · track · 37EPSS 0.078 · 95 %ileEUUS

grimoire priorityP2 · Scheduled

Exploitable?

—

no known exploitation

Likely / severe?

7.77% (95th) EPSS

CVSS 7.4 · high

Is it mine?

2 products

Check your exposure

Who says so?

3 sources

cnnvd · enisa_euvd · nvd

EPSS · scored 2026-10-24

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.

cvss

Technical severity, 0–10. One row per scoring source.

8.4

010

base score 0–10 · higher = more severe · hover a vector to decode

v2.07.4highAV:A/AC:M/Au:S/C:C/I:C/A:Cprimary · NVD / NIST USexploitability 4.4 · impact 10

v3.18.4highCVSS:3.1/AV:A/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:Hprimary · NVD / NIST USexploitability 1.7 · impact 6

v3.17.7highCVSS:3.1/AV:A/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H/E:Usecondary · CVSS-BT (t0sche)

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-22USprimary

affected products (2)

Products and version ranges known to be affected.

n/a Quagga Services on D-Link DIR-2640 Routers≤ ≤ 1.11B02enisa_euvdEU
dlink dir-2640-us firmware≤ 1.11b02nvdUScpe:2.3:o:dlink:dir-2640-us_firmware:*:*:*:*:*:*:*:*

also known as (3)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd nvd NVD CVE.org MITRE

published 2021-12-30modified 2026-06-17

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+12484 more

references (4)

External citations — patches, advisories, analysis.

scry

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