Severity by source
AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Remote, unauthenticated, no interaction against the exposed web service (AV:N/AC:L/PR:N/UI:N); impact is a crash/DoS so A:H with C:N/I:N, correcting the input vector's C:H.
Primary rating from Vendor (mitre).
CVSS VectorVendor: mitre
Lifecycle Timeline
3DescriptionCVE.org
Buffer Overflow vulnerability in UTT nv518G nv518GV3v3.2.7-210919-161313 allows a remote attacker to cause a denial of service via the gohead/sub_447CAC component
AnalysisAI
Denial of service in the UTT nv518G gateway/router (firmware nv518GV3v3.2.7-210919-161313) allows a remote attacker to crash the device by triggering a buffer overflow in the gohead/sub_447CAC web-server routine. Publicly available exploit code exists (referenced GitHub CVEreport analysis) but it is not listed in CISA KEV; EPSS is low at 0.22% (13th percentile), indicating no observed widespread exploitation. Note a data conflict: the description and tags describe a DoS, yet the supplied CVSS vector encodes a confidentiality impact (C:H/A:N) rather than availability.
Technical ContextAI
The affected component 'gohead' points to the embedded GoAhead/goahead-style HTTP server that ships on UTT's nv-series enterprise routers/VPN gateways, and sub_447CAC/FUN_00447048 is a disassembler-derived label for the vulnerable handler function reverse-engineered from the firmware binary. The root cause is CWE-120 (Classic Buffer Overflow / copy without checking input size), meaning attacker-supplied data reaching this handler is written into a fixed-size stack or heap buffer without bounds validation, corrupting adjacent memory and crashing the web service or device. Because the flaw lives in the management/web interface parser, it is reachable over the network wherever that interface is exposed.
RemediationAI
No vendor-released patch version is identified in the available data, so the primary action is to check the UTT download center (https://utt.com.cn/downloadcenter.php?filetypeid=3&model=518G&lang=zhcn) for a firmware build newer than v3.2.7-210919-161313 and apply it once published. As compensating controls until a fix exists: restrict access to the device web/management interface (the gohead HTTP service) so it is not reachable from the WAN or untrusted networks - bind management to a dedicated LAN/VLAN or management IP allowlist, which prevents remote triggering at the cost of requiring on-network access for administration; block inbound access to the management HTTP port at the perimeter firewall, with the side effect of disabling any legitimate remote administration; and monitor the device for unexpected reboots or web-service crashes as a detection fallback. Because the flaw is a crash rather than code execution per the description, the practical goal is limiting network reachability of the vulnerable endpoint.
Same weakness CWE-120 – Classic Buffer Overflow
View allSame technique Buffer Overflow
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External POC / Exploit Code
Leaving vuln.today
EUVD-2026-40864
GHSA-wj3w-v66w-x298