Attackers increasingly exploiting vulnerabilities to enlarge their IoT botnets

The Realtek SDK, a software development kit embedded in routers, gateways, and similar network equipment sold under many OEM brands, contains an improper input validation flaw (CWE-20) in its miniigd UPnP SOAP service. A remote, unauthenticated attacker can trigger it by sending a crafted NewInternalClient request to the vulnerable SOAP interface, causing execution of malicious code on the device. Successful exploitation gives attackers control of affected devices, which can be used for botnet recruitment, staging further attacks, or ransomware operations. Affected parties are owners of devices built on the Realtek SDK, particularly routers and gateways with the UPnP service exposed to the internet. Exploitation is ongoing: CISA added the flaw to the Known Exploited Vulnerabilities catalog on 2023-09-18 and EPSS assigns it a 100% probability of exploitation within 30 days, though ransomware use is not confirmed.

Do: Inventory devices that use the Realtek SDK and check whether the miniigd UPnP/SOAP service is reachable from untrusted networks; apply firmware updates from your device vendor as soon as available, or per CISA's required action, disable UPnP or block the service from internet exposure if mitigations are unavailable. No patch level is published in this dataset, so verify fix status against OEM advisories and review device logs for crafted NewInternalClient SOAP requests.

The D-Link DIR-645 wired/wireless router is vulnerable to OS command injection (CWE-77) in its HNAP interface: input supplied to the GetDeviceSettings action is not properly neutralized, so a remote attacker who sends a crafted HTTP request to the router's HNAP endpoint can have arbitrary operating-system commands executed on the device. Successful exploitation gives the attacker control of the router at the system level, enabling reconfiguration or abuse of the device, traffic interception or redirection, and recruitment into IoT botnets, as reflected in recent Moobot/MooBot botnet campaigns. Any site or household still running a DIR-645, especially one whose web/HNAP management interface is reachable from the internet, is affected; the product is end-of-life. The flaw is under active exploitation: it was added to CISA's Known Exploited Vulnerabilities catalog on 2022-02-10, and EPSS assigns a 97.1% probability of exploitation within 30 days (100th percentile). CISA's required action reflects the risk: disconnect the impacted product if it is still in use because it has reached end-of-life.

Do: Because the DIR-645 is end-of-life, CISA's required action is to disconnect it; replace the device where possible, or at minimum apply the latest available D-Link firmware for the DIR-645 and ensure the management/HNAP interface is not reachable from the internet (block or restrict remote administration on the WAN side). Check the device for signs of botnet infection, such as unexpected outbound traffic or unexpected HNAP POST/SOAP requests, and prioritize this fix given the 97.1% EPSS score and known in-the-wild exploitation.

Huawei HG532 with some customized versions has a remote code execution vulnerability. An authenticated attacker could send malicious packets to port 37215 to launch attacks. Successful exploit could lead to the remote execution of arbitrary code.

CVE-2018-10561 is a critical authentication bypass (CWE-287, CVSS 9.8) in Dasan GPON home router firmware: the devices fail to properly enforce login when a specific suffix is added to a URL. An attacker simply appends "?images" to any protected URL — for example /menu.html?images/ or /GponForm/diag_FORM?images/ — and the router treats the request as already authenticated. Once bypassed, the attacker gains full access to the device's management interface, enabling configuration changes, diagnostics, and use of the router as a botnet node or network pivot. All Dasan Gigabit Passive Optical Network (GPON) routers running the affected firmware are exposed, especially units with their web interface reachable from the internet; CISA notes the impacted product is end-of-life. Exploitation is active and widespread: the flaw is in CISA's Known Exploited Vulnerabilities catalog (added 2022-03-31), carries a 92.9% EPSS probability of exploitation within 30 days, and IoT botnets have historically targeted these routers.

Do: CISA's required action is to disconnect or replace these routers if still in use, since the product is end-of-life and should not remain deployed. As an interim mitigation, remove the device's web management interface from internet exposure and block or strip requests containing "?images"; verify exposure by loading /menu.html?images/ without logging in — if it returns the management page, the device is vulnerable. A community mitigation tool and unofficial patch have been published by researchers, but replacement remains the recommended fix, and defenders should expect continued botnet scanning of exposed units.