CVE-2021-20132

Root service access via hard-coded Quagga credentials

Published Dec 30, 2021 · Updated Aug 3, 2024

Hard-coded credentials in Quagga on D-Link DIR-2640 1.11B02 and earlier allow remote attackers to gain root-level service access. The zebra and ripd daemons listen on TCP ports 2601 and 2602 by default and accept a discoverable fixed password for command-line and enable-mode access. An attacker on an adjacent network needs no existing account or user interaction and gains complete control of both root-privileged routing services.

CVSS severity8.8
High
EPSS probability4.29%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Hard-coded credentials in Quagga on D-Link DIR-2640 1.11B02 and earlier allow remote attackers to gain root-level service access. The zebra and ripd daemons listen on TCP ports 2601 and 2602 by default and accept a discoverable fixed password for command-line and enable-mode access. An attacker on an adjacent network needs no existing account or user interaction and gains complete control of both root-privileged routing services.

The record

CVE
CVE-2021-20132
Published
Dec 30, 2021
Updated
Aug 3, 2024
Vendor
D-Link
Product
DIR-2640
Classifications
CWE-798, T1078.001
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Dec 30, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 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?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=<= 1.11B02

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

D-Link · DIR-2640version=<= 1.11B02

Published CVSS scores

8.8TenableCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
8.8NIST NVDCVSS:3.1/AV:A/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)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-798Use of Hard-coded Credentials
T1078.001Valid Accounts: Default Accounts

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

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo