CVE-2021-47880
Published: 21 January 2026
Summary
CVE-2021-47880 is a high-severity Unquoted Search Path or Element (CWE-428) vulnerability in Realtek Wireless LAN (inferred from references). Its CVSS base score is 8.5 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Path Interception by Unquoted Path (T1574.009); ranked at the 2.7th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
The strongest mitigations our analysis identified are NIST 800-53 CM-6 (Configuration Settings) and CM-7 (Least Functionality).
Deeper analysis
CVE-2021-47880 is an unquoted service path vulnerability (CWE-428) in Realtek Wireless LAN Utility version 700.1631. The issue arises in a Windows service where the path to the executable lacks proper quotation, enabling local privilege escalation.
A local attacker with low privileges (PR:L) can exploit this vulnerability with low complexity (AC:L) and no user interaction (UI:N). By placing a malicious executable in the system root path, the attacker causes it to execute with SYSTEM privileges during service startup, such as application launch or system reboot, resulting in high impacts on confidentiality, integrity, and availability (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H, score 7.8).
Advisories from VulnCheck describe the unquoted service path in the Realteknsu service, and a public exploit is available on Exploit-DB at https://www.exploit-db.com/exploits/49646. The Realtek website at https://www.realtek.com/en/ provides vendor context but no specific patch details in the references.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-3631
Vulnerability details
Realtek Wireless LAN Utility 700.1631 contains an unquoted service path vulnerability that allows local users to potentially execute code with elevated system privileges. Attackers can exploit the unquoted service path by inserting malicious code in the system root path that…
more
would execute during application startup or system reboot.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Unquoted service path directly enables path interception by unquoted path (T1574.009) for local privilege escalation via malicious executable execution with SYSTEM rights (T1068).
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Directly remediates the unquoted service path flaw in the Realtek Wireless LAN Utility by identifying, reporting, and applying patches or mitigations.
Ensures secure configuration settings for Windows services, including proper quoting of executable paths to block exploitation of unquoted service paths.
Limits system functionality by disabling or restricting non-essential services like the vulnerable Realteknsu service, preventing its startup and potential exploitation.