CVE-2021-27253

This vulnerability allows network-adjacent attackers to execute arbitrary code on affected installations of NETGEAR Nighthawk R7800. Although authentication is required to exploit this vulnerability, the existing authentication mechanism can be bypassed. The specific flaw exists within the handling of the rc_service parameter provided to apply_bind.cgi. The issue results from the lack of proper validation of a user-supplied string before using it to execute a system call. An attacker can leverage this vulnerability to execute code in the context of root. Was ZDI-CAN-12303.

• CWE-122
• CWE-787

• https://kb.netgear.com/000062883/Security-Advisory-for-Multiple-Vulnerabilities-on-Some-Routers-Satellites-and-ExtendersPatch, Vendor Advisory
• https://www.zerodayinitiative.com/advisories/ZDI-21-249/Third Party Advisory, VDB Entry
• https://kb.netgear.com/000062883/Security-Advisory-for-Multiple-Vulnerabilities-on-Some-Routers-Satellites-and-ExtendersPatch, Vendor Advisory
• https://www.zerodayinitiative.com/advisories/ZDI-21-249/Third Party Advisory, VDB Entry

Published

Apr 14, 2021

Last Modified

Jun 17, 2026

Status

Modified

• How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
• Autonomous PentestingAI agents that find and validate exploitable vulnerabilities like this one across your applications.
• PR ReviewsPentest every pull request so vulnerable code is caught before it ships to production.
• AI Penetration TestingHow AI-driven penetration testing continuously covers your attack surface.

• CVE-2021-27247This vulnerability allows remote attackers to disclose sensi…6.5
• CVE-2021-27248This vulnerability allows network-adjacent attackers to exec…8.8
• CVE-2021-27249This vulnerability allows network-adjacent attackers to exec…8.8
• CVE-2021-27250This vulnerability allows network-adjacent attackers to disc…6.5
• CVE-2021-27251This vulnerability allows network-adjacent attackers to exec…8.8
• CVE-2021-27252This vulnerability allows network-adjacent attackers to exec…8.8
• CVE-2021-27254This vulnerability allows network-adjacent attackers to bypa…8.8
• CVE-2021-27255This vulnerability allows remote attackers to execute arbitr…8.8
• CVE-2021-27256This vulnerability allows network-adjacent attackers to exec…8.8
• CVE-2021-27257This vulnerability allows network-adjacent attackers to comp…6.5
• CVE-2021-27258This vulnerability allows remote attackers to execute escala…9.8
• CVE-2021-27259This vulnerability allows local attackers to escalate privil…7.8