Vulnerability Monitor

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CVE-2021-27256

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.

Security Impact Summary

This vulnerability carries a HIGH severity rating with a CVSS v3.1 score of 8.8, indicating it requires adjacent network access with relatively low complexity without requiring user interaction and does not require pre-existing privileges . The vulnerability impacts confidentiality (data exposure), integrity (unauthorized modifications), and availability (service disruption) for affected systems. Impacting 86 products from netgear, from netgear, from netgear and 83 others, organizations running these solutions should prioritize assessment and patching.

Historical Context

Reported in 2021, this vulnerability emerged during an era marked by increased sophistication in supply chain attacks, cloud infrastructure vulnerabilities, and software-as-a-service (SaaS) security challenges. Security practices during this period emphasized zero-trust architectures, container security, and API protection.

Published

2021-03-05T20:15:12.550

Last Modified

2024-11-21T05:57:42.160

Status

Modified

Source

[email protected]

Severity

CVSSv3.1: 8.8 (HIGH)

CVSSv2 Vector

AV:A/AC:L/Au:N/C:C/I:C/A:C

  • Access Vector: ADJACENT_NETWORK
  • Access Complexity: LOW
  • Authentication: NONE
  • Confidentiality Impact: COMPLETE
  • Integrity Impact: COMPLETE
  • Availability Impact: COMPLETE
Exploitability Score

6.5

Impact Score

10.0

Weaknesses
  • Type: Secondary
    CWE-78
Affected Vendors & Products
Type Vendor Product Version/Range Vulnerable?
Operating System netgear br200_firmware < 5.10.0.5 Yes
Hardware netgear br200 - No
Operating System netgear br500_firmware < 5.10.0.5 Yes
Hardware netgear br500 - No
Operating System netgear d7800_firmware < 1.0.1.60 Yes
Hardware netgear d7800 - No
Operating System netgear ex6100v2_firmware < 1.0.1.98 Yes
Hardware netgear ex6100v2 - No
Operating System netgear ex6150v2_firmware < 1.0.1.98 Yes
Hardware netgear ex6150v2 - No
Operating System netgear ex6250_firmware < 1.0.0.134 Yes
Hardware netgear ex6250 - No
Operating System netgear ex6400_firmware < 1.0.2.158 Yes
Hardware netgear ex6400 - No
Operating System netgear ex6400v2_firmware < 1.0.0.134 Yes
Hardware netgear ex6400v2 - No
Operating System netgear ex6410_firmware < 1.0.0.134 Yes
Hardware netgear ex6410 - No
Operating System netgear ex6420_firmware < 1.0.0.134 Yes
Hardware netgear ex6420 - No
Operating System netgear ex7300_firmware < 1.0.2.158 Yes
Hardware netgear ex7300 - No
Operating System netgear ex7300v2_firmware < 1.0.0.134 Yes
Hardware netgear ex7300v2 - No
Operating System netgear ex7320_firmware < 1.0.0.134 Yes
Hardware netgear ex7320 - No
Operating System netgear ex7700_firmware < 1.0.0.216 Yes
Hardware netgear ex7700 - No
Operating System netgear ex8000_firmware < 1.0.1.232 Yes
Hardware netgear ex8000 - No
Operating System netgear lbr20_firmware < 2.6.3.50 Yes
Hardware netgear lbr20 - No
Operating System netgear r7800_firmware < 1.0.2.80 Yes
Hardware netgear r7800 - No
Operating System netgear r8900_firmware < 1.0.5.28 Yes
Hardware netgear r8900 - No
Operating System netgear r9000_firmware < 1.0.5.28 Yes
Hardware netgear r9000 - No
Operating System netgear rbk12_firmware < 2.7.2.104 Yes
Hardware netgear rbk12 - No
Operating System netgear rbk13_firmware < 2.7.2.104 Yes
Hardware netgear rbk13 - No
Operating System netgear rbk14_firmware < 2.7.2.104 Yes
Hardware netgear rbk14 - No
Operating System netgear rbk15_firmware < 2.7.2.104 Yes
Hardware netgear rbk15 - No
Operating System netgear rbk20_firmware < 2.6.2.104 Yes
Hardware netgear rbk20 - No
Operating System netgear rbk23_firmware < 2.7.2.104 Yes
Hardware netgear rbk23 - No
Operating System netgear rbk40_firmware < 2.6.2.104 Yes
Hardware netgear rbk40 - No
Operating System netgear rbk43_firmware < 2.6.2.104 Yes
Hardware netgear rbk43 - No
Operating System netgear rbk43s_firmware < 2.6.2.104 Yes
Hardware netgear rbk43s - No
Operating System netgear rbk44_firmware < 2.6.2.104 Yes
Hardware netgear rbk44 - No
Operating System netgear rbk50_firmware < 2.7.2.104 Yes
Hardware netgear rbk50 - No
Operating System netgear rbk53_firmware < 2.7.2.104 Yes
Hardware netgear rbk53 - No
Operating System netgear rbr10_firmware < 2.6.2.104 Yes
Hardware netgear rbr10 - No
Operating System netgear rbr20_firmware < 2.6.2.104 Yes
Hardware netgear rbr20 - No
Operating System netgear rbr40_firmware < 2.6.2.104 Yes
Hardware netgear rbr40 - No
Operating System netgear rbr50_firmware < 2.7.2.104 Yes
Hardware netgear rbr50 - No
Operating System netgear rbs10_firmware < 2.6.2.104 Yes
Hardware netgear rbs10 - No
Operating System netgear rbs20_firmware < 2.6.2.104 Yes
Hardware netgear rbs20 - No
Operating System netgear rbs40_firmware < 2.6.2.104 Yes
Hardware netgear rbs40 - No
Operating System netgear rbs50_firmware < 2.7.2.104 Yes
Hardware netgear rbs50 - No
Operating System netgear rbs50y_firmware < 2.6.2.104 Yes
Hardware netgear rbs50y - No
Operating System netgear xr450_firmware < 2.3.2.114 Yes
Hardware netgear xr450 - No
Operating System netgear xr500_firmware < 2.3.2.114 Yes
Hardware netgear xr500 - No
Operating System netgear xr700_firmware < 1.0.1.38 Yes
Hardware netgear xr700 - No
References

How SecUtils Interprets This CVE

SecUtils normalizes and enriches National Vulnerability Database (NVD) records by standardizing vendor and product identifiers, aggregating vulnerability metadata from both NVD and MITRE sources, and providing structured context for security teams. For netgear's affected products, we extract Common Platform Enumeration (CPE) data, Common Weakness Enumeration (CWE) classifications, CVSS severity metrics, and reference data to enable rapid vulnerability prioritization and asset correlation. This record contains no exploit code, proof-of-concept instructions, or attack methodologies—only defensive intelligence necessary for patch management, risk assessment, and security operations.