{"description":"Trending threats, MITRE ATT\u0026CK coverage, and detection metadata — refreshed continuously.","feed_url":"https://feed.craftedsignal.io/tags/cve-2026-6581/","home_page_url":"https://feed.craftedsignal.io/","items":[{"_cs_actors":[],"_cs_cves":[{"cvss":8.8,"id":"CVE-2026-6581"}],"_cs_exploited":false,"_cs_products":[],"_cs_severities":["critical"],"_cs_tags":["cve-2026-6581","buffer-overflow","router","h3c"],"_cs_type":"advisory","_cs_vendors":[],"content_html":"\u003cp\u003eA critical buffer overflow vulnerability, identified as CVE-2026-6581, affects H3C Magic B1 routers up to version 100R004. The vulnerability resides in the \u003ccode\u003eSetMobileAPInfoById\u003c/code\u003e function within the \u003ccode\u003e/goform/aspForm\u003c/code\u003e file. An attacker can exploit this flaw by crafting a malicious request that manipulates the \u003ccode\u003eparam\u003c/code\u003e argument, leading to a buffer overflow and potential remote code execution. This vulnerability is particularly concerning because a public exploit is available, increasing the risk of widespread exploitation. The vendor was notified about the vulnerability but has not responded. Given the ease of exploitation and the potential for complete system compromise, organizations using affected H3C routers should take immediate action.\u003c/p\u003e\n\u003ch2 id=\"attack-chain\"\u003eAttack Chain\u003c/h2\u003e\n\u003col\u003e\n\u003cli\u003eThe attacker identifies a vulnerable H3C Magic B1 router running a firmware version up to 100R004.\u003c/li\u003e\n\u003cli\u003eThe attacker crafts a malicious HTTP POST request targeting the \u003ccode\u003e/goform/aspForm\u003c/code\u003e endpoint.\u003c/li\u003e\n\u003cli\u003eThe request includes the \u003ccode\u003eSetMobileAPInfoById\u003c/code\u003e function call with an overly long value for the \u003ccode\u003eparam\u003c/code\u003e argument, triggering the buffer overflow.\u003c/li\u003e\n\u003cli\u003eThe overflow overwrites adjacent memory regions, including the return address on the stack.\u003c/li\u003e\n\u003cli\u003eThe attacker sets the overwritten return address to point to attacker-controlled code or a ROP chain.\u003c/li\u003e\n\u003cli\u003eWhen the \u003ccode\u003eSetMobileAPInfoById\u003c/code\u003e function returns, execution jumps to the attacker-controlled code.\u003c/li\u003e\n\u003cli\u003eThe attacker\u0026rsquo;s code executes with elevated privileges, potentially allowing full control of the router.\u003c/li\u003e\n\u003cli\u003eThe attacker can then use the compromised router to establish a foothold within the network, exfiltrate data, or launch further attacks.\u003c/li\u003e\n\u003c/ol\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eSuccessful exploitation of CVE-2026-6581 allows a remote attacker to execute arbitrary code with root privileges on the H3C Magic B1 router. This can lead to complete compromise of the device, allowing the attacker to control network traffic, exfiltrate sensitive data, or use the router as a jumping-off point for further attacks within the network. Given the widespread use of these routers in small to medium-sized businesses and homes, a large number of devices are potentially vulnerable. There is no indication of victim counts or sectors targeted at this time.\u003c/p\u003e\n\u003ch2 id=\"recommendation\"\u003eRecommendation\u003c/h2\u003e\n\u003cul\u003e\n\u003cli\u003eDeploy the Sigma rule \u003ccode\u003eDetect H3C Magic B1 Buffer Overflow Attempt\u003c/code\u003e to your SIEM to detect exploitation attempts targeting CVE-2026-6581 via suspicious HTTP POST requests to \u003ccode\u003e/goform/aspForm\u003c/code\u003e (see Sigma rule below).\u003c/li\u003e\n\u003cli\u003eApply appropriate input validation and sanitization measures if you manage the web server to mitigate buffer overflows.\u003c/li\u003e\n\u003cli\u003eMonitor network traffic for unusual activity originating from H3C Magic B1 routers.\u003c/li\u003e\n\u003cli\u003eConsider replacing H3C Magic B1 routers with more secure alternatives if updates are not available.\u003c/li\u003e\n\u003c/ul\u003e\n","date_modified":"2026-04-19T23:16:33Z","date_published":"2026-04-19T23:16:33Z","id":"/briefs/2026-04-h3c-magic-b1-overflow/","summary":"A buffer overflow vulnerability (CVE-2026-6581) in H3C Magic B1 routers allows remote attackers to execute arbitrary code by manipulating the 'param' argument in the SetMobileAPInfoById function.","title":"H3C Magic B1 Router Buffer Overflow Vulnerability","url":"https://feed.craftedsignal.io/briefs/2026-04-h3c-magic-b1-overflow/"}],"language":"en","title":"CraftedSignal Threat Feed — Cve-2026-6581","version":"https://jsonfeed.org/version/1.1"}