CVE-2021-27137
An issue was discovered in router/upnp/src/ssdp.c in DD-WRT before 45724. An unsafe strcpy in the UPnP handling functionality allows an unauthenticated remote attacker to send a request that would overflow an internal fixed buffer. Exploitation requires the DD-WRT user to enable UPnP (which is off by default, and only listens on internal interfaces by default). This occurs in ssdp_msearch (reachable by an M-SEARCH request).
Scoring
- Severity
- HIGH
- CVSS base score
- 8.1
- CVSS vector
- CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
- EPSS probability
- 4.00%
- CISA KEV
- Known exploited vulnerability
- CWE
- CWE-121
- Published
- 2026-07-16
- Last modified
- 2026-07-22
Affected products
- DD-WRT DD-WRT
Weakness type
Related vulnerabilities
- CVE-2026-85384 — Authenticated Stack-Based Buffer Overflow in RE210 AC750 Configuration Import
- CVE-2026-83990 — Microsoft Graphics Component Elevation of Privilege Vulnerability
- CVE-2026-81953 — Microsoft Excel Remote Code Execution Vulnerability
- CVE-2026-81388 — Microsoft Excel Remote Code Execution Vulnerability
- CVE-2026-81396 — Microsoft Excel Remote Code Execution Vulnerability
- CVE-2026-73006 — DirectWrite Remote Code Execution Vulnerability
- CVE-2026-69614 — Microsoft Office Access Remote Code Execution Vulnerability
- CVE-2026-69510 — Windows DHCP Server Remote Code Execution Vulnerability