CVE-2021-27137

Exploitation active confirmée

Ajoutée au catalogue CISA KEV le 21/07/2026, correctif exigé avant le 24/07/2026 pour les agences fédérales américaines.

Action requise : Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.

Description officielle (NVD)

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).

Références

• https://securityaffairs.com/193290/uncategorized/iot-botnet-c0xmo-adds-competitor-killing-capability.html , Exploit, Third Party Advisory
• https://ssd-disclosure.com/ssd-advisory-dd-wrt-upnp-buffer-overflow/ , Exploit, Third Party Advisory
• https://svn.dd-wrt.com/changeset/45724 , Patch
• https://www.bleepingcomputer.com/news/security/c0xmo-botnet-spreads-via-dd-wrt-router-flaw-kills-rival-malware... , Exploit, Third Party Advisory
• https://www.fortinet.com/blog/threat-research/inside-cross-platform-propagation-of-new-gafgyt-variant-c0xmo , Exploit
• https://ssd-disclosure.com/ssd-advisory-dd-wrt-upnp-buffer-overflow/ , Exploit, Third Party Advisory
• https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-27137 , US Government Resource

En bref

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS : probabilité estimée d'exploitation dans les 30 prochains jours.

Produits concernés

Sources officielles

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