CVE-2021-47854: DD-WRT 45723 - UPNP Buffer Overflow

Published Jan 21, 2026
·
Updated

DD-WRT version 45723 contains a buffer overflow vulnerability in the UPNP network discovery service that allows remote attackers to potentially execute arbitrary code. Attackers can send crafted M-SEARCH packets with oversized UUID payloads to trigger buffer overflow conditions on the target device.

Affected Software

1 affected component
DD-WRT DD-WRT

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade DD-WRT to a version that resolves this vulnerability.

    Fixed in 45723Patch DD-WRT 45723 - UPNP Buffer Overflow

Event History

Jan 21, 2026
CVE Published
via MITRE·05:27 PM
Data Sourced
via MITRE·05:27 PM
DescriptionSeverityWeakness
Data Sourced
via NVD·06:16 PM
DescriptionSeverityWeakness
Nov 24, 58540
Event
via NVD·05:48 PM
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Frequently Asked Questions

1

What is the severity of CVE-2021-47854?

CVE-2021-47854 is classified as a high-severity vulnerability due to its potential to allow remote code execution.

2

How do I fix CVE-2021-47854?

To fix CVE-2021-47854, you should upgrade to the latest DD-WRT firmware version that addresses this buffer overflow issue.

3

What systems are affected by CVE-2021-47854?

CVE-2021-47854 specifically affects DD-WRT version 45723 and potentially other versions if they utilize the same UPNP network discovery service.

4

How is CVE-2021-47854 exploited?

CVE-2021-47854 can be exploited by attackers sending crafted M-SEARCH packets with oversized UUID payloads.

5

What are the potential consequences of CVE-2021-47854?

The potential consequences of CVE-2021-47854 include unauthorized remote code execution which could compromise the security of the device.

Contact

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