Vulnerability Description
This vulnerability allows network-adjacent attackers to execute arbitrary code on affected installations of NETGEAR R7800 firmware version 1.0.2.76. 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_save.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-12355.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Netgear | Br200 Firmware | < 5.10.0.5 |
| Netgear | Br200 | - |
| Netgear | Br500 Firmware | < 5.10.0.5 |
| Netgear | Br500 | - |
| Netgear | D7800 Firmware | < 1.0.1.60 |
| Netgear | D7800 | - |
| Netgear | Ex6100V2 Firmware | < 1.0.1.98 |
| Netgear | Ex6100V2 | - |
| Netgear | Ex6150V2 Firmware | < 1.0.1.98 |
| Netgear | Ex6150V2 | - |
| Netgear | Ex6250 Firmware | < 1.0.0.134 |
| Netgear | Ex6250 | - |
| Netgear | Ex6400 Firmware | < 1.0.2.158 |
| Netgear | Ex6400 | - |
| Netgear | Ex6400V2 Firmware | < 1.0.0.134 |
| Netgear | Ex6400V2 | - |
| Netgear | Ex6410 Firmware | < 1.0.0.134 |
| Netgear | Ex6410 | - |
| Netgear | Ex6420 Firmware | < 1.0.0.134 |
| Netgear | Ex6420 | - |
Related Weaknesses (CWE)
References
- https://kb.netgear.com/000062883/Security-Advisory-for-Multiple-Vulnerabilities-PatchVendor Advisory
- https://www.zerodayinitiative.com/advisories/ZDI-21-262/Third Party AdvisoryVDB Entry
- https://kb.netgear.com/000062883/Security-Advisory-for-Multiple-Vulnerabilities-PatchVendor Advisory
- https://www.zerodayinitiative.com/advisories/ZDI-21-262/Third Party AdvisoryVDB Entry
FAQ
What is CVE-2021-27256?
CVE-2021-27256 is a vulnerability with a CVSS score of 8.8 (HIGH). This vulnerability allows network-adjacent attackers to execute arbitrary code on affected installations of NETGEAR R7800 firmware version 1.0.2.76. Although authentication is required to exploit this...
How severe is CVE-2021-27256?
CVE-2021-27256 has been rated HIGH with a CVSS base score of 8.8/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2021-27256?
Check the references section above for vendor advisories and patch information. Affected products include: Netgear Br200 Firmware, Netgear Br200, Netgear Br500 Firmware, Netgear Br500, Netgear D7800 Firmware.