Vulnerability · Published Jan 21, 2026 · Assigned by VulnCheck
CVE-2021-47854DD-WRT 45723 - UPNP Buffer Overflow
Critical 9.8
In plain English
A critical-severity buffer overflow in DD-WRT from embeDD GmbH. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 1.1% (higher than 65% of all known vulnerabilities).
Severity (CVSS 3.1)9.8Critical
Exploit odds (30 days)1.1%top 34.7% of all CVEs
Exploited in the wildNo reportsCISA SSVC: poc
Attack toolingNoneno public tooling known
Official description
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 products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| embeDD GmbH | DD-WRT | 45723 |
Weakness: CWE-120 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
References
- ExploitDB-49730 exploit
- DD-WRT Official Vendor Homepage product
- DD-WRT Software Download Repository product
- SSD Security Advisory for DD-WRT UPNP Buffer Overflow technical-description
- VulnCheck Advisory: DD-WRT 45723 - UPNP Buffer Overflow third-party-advisory