CVE-2021-27137

DD-WRT Stack-Based Buffer Overflow Vulnerability

Dd-Wrt

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).

16. Jul 2026

Ausgewertete Quellen

• Hinweis
  https://securityaffairs.com/193290/uncategorized/iot-botnet-c0xmo-adds-competitor-killing-capability.html
• Hinweis
  https://ssd-disclosure.com/ssd-advisory-dd-wrt-upnp-buffer-overflow/
• Hinweis
  https://www.bleepingcomputer.com/news/security/c0xmo-botnet-spreads-via-dd-wrt-router-flaw-kills-rival-malware/
• CISA
  https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-27137
• CISA
  DD-WRT Stack-Based Buffer Overflow Vulnerability
• NVD
  CVE-2021-27137