CVE-2021-27257 : This vulnerability allows network-adjacent attackers to compromise the integrity

This vulnerability allows network-adjacent attackers to compromise the integrity of downloaded information on affected installations of NETGEAR R7800 firmware version 1.0.2.76. Authentication is not required to exploit this vulnerability. The specific flaw exists within the downloading of files via FTP. The issue results from the lack of proper validation of the certificate presented by the server. An attacker can leverage this in conjunction with other vulnerabilities to execute arbitrary code in the context of root. Was ZDI-CAN-12362.

Published 2021-03-05 20:15:13

Updated 2021-03-17 14:04:46

Source Zero Day Initiative

View at NVD, CVE.org

Vulnerability category: Execute code

Products affected by CVE-2021-27257

Netgear » R7800 Firmware
Versions before (<) 1.0.2.80
cpe:2.3:o:netgear:r7800_firmware:*:*:*:*:*:*:*:*
Matching versions
When used together with: Netgear » R7800 » Version: N/A
Netgear » R9000 Firmware
Versions before (<) 1.0.5.28
cpe:2.3:o:netgear:r9000_firmware:*:*:*:*:*:*:*:*
Matching versions
When used together with: Netgear » R9000 » Version: N/A
Netgear » D7800 Firmware
Versions before (<) 1.0.1.60
cpe:2.3:o:netgear:d7800_firmware:*:*:*:*:*:*:*:*
Matching versions
When used together with: Netgear » D7800 » Version: N/A
Netgear » Ex6400 Firmware
Versions before (<) 1.0.2.158
cpe:2.3:o:netgear:ex6400_firmware:*:*:*:*:*:*:*:*
Matching versions
When used together with: Netgear » Ex6400 » Version: N/A
Netgear » Ex7300 Firmware
Versions before (<) 1.0.2.158
cpe:2.3:o:netgear:ex7300_firmware:*:*:*:*:*:*:*:*
Matching versions
When used together with: Netgear » Ex7300 » Version: N/A
Netgear » Ex8000 Firmware
Versions before (<) 1.0.1.232
cpe:2.3:o:netgear:ex8000_firmware:*:*:*:*:*:*:*:*
Matching versions
When used together with: Netgear » Ex8000 » Version: N/A
Netgear » R8900 Firmware
Versions before (<) 1.0.5.28
cpe:2.3:o:netgear:r8900_firmware:*:*:*:*:*:*:*:*
Matching versions
When used together with: Netgear » R8900 » Version: N/A
Netgear » Xr500 Firmware
Versions before (<) 2.3.2.114
cpe:2.3:o:netgear:xr500_firmware:*:*:*:*:*:*:*:*
Matching versions
When used together with: Netgear » Xr500 » Version: N/A
Netgear » Xr700 Firmware
Versions before (<) 1.0.1.38
cpe:2.3:o:netgear:xr700_firmware:*:*:*:*:*:*:*:*
Matching versions
When used together with: Netgear » Xr700 » Version: N/A
Netgear » Rbr20 Firmware
Versions before (<) 2.6.2.104
cpe:2.3:o:netgear:rbr20_firmware:*:*:*:*:*:*:*:*
Matching versions
When used together with: Netgear » Rbr20 » Version: N/A
Netgear » Rbs20 Firmware
Versions before (<) 2.6.2.104
cpe:2.3:o:netgear:rbs20_firmware:*:*:*:*:*:*:*:*
Matching versions
When used together with: Netgear » Rbs20 » Version: N/A
Netgear » Rbk20 Firmware
Versions before (<) 2.6.2.104
cpe:2.3:o:netgear:rbk20_firmware:*:*:*:*:*:*:*:*
Matching versions
When used together with: Netgear » Rbk20 » Version: N/A
Netgear » Rbr40 Firmware
Versions before (<) 2.6.2.104
cpe:2.3:o:netgear:rbr40_firmware:*:*:*:*:*:*:*:*
Matching versions
When used together with: Netgear » Rbr40 » Version: N/A
Netgear » Rbs40 Firmware
Versions before (<) 2.6.2.104
cpe:2.3:o:netgear:rbs40_firmware:*:*:*:*:*:*:*:*
Matching versions
When used together with: Netgear » Rbs40 » Version: N/A
Netgear » Rbk40 Firmware
Versions before (<) 2.6.2.104
cpe:2.3:o:netgear:rbk40_firmware:*:*:*:*:*:*:*:*
Matching versions
When used together with: Netgear » Rbk40 » Version: N/A
Netgear » Rbr50 Firmware
Versions before (<) 2.7.2.104
cpe:2.3:o:netgear:rbr50_firmware:*:*:*:*:*:*:*:*
Matching versions
When used together with: Netgear » Rbr50 » Version: N/A
Netgear » Rbs50 Firmware
Versions before (<) 2.7.2.104
cpe:2.3:o:netgear:rbs50_firmware:*:*:*:*:*:*:*:*
Matching versions
When used together with: Netgear » Rbs50 » Version: N/A
Netgear » Rbk50 Firmware
Versions before (<) 2.7.2.104
cpe:2.3:o:netgear:rbk50_firmware:*:*:*:*:*:*:*:*
Matching versions
When used together with: Netgear » Rbk50 » Version: N/A
Netgear » Xr450 Firmware
Versions before (<) 2.3.2.114
cpe:2.3:o:netgear:xr450_firmware:*:*:*:*:*:*:*:*
Matching versions
When used together with: Netgear » Xr450 » Version: N/A
Netgear » Br200 Firmware
Versions before (<) 5.10.0.5
cpe:2.3:o:netgear:br200_firmware:*:*:*:*:*:*:*:*
Matching versions
When used together with: Netgear » Br200 » Version: N/A
Netgear » Br500 Firmware
Versions before (<) 5.10.0.5
cpe:2.3:o:netgear:br500_firmware:*:*:*:*:*:*:*:*
Matching versions
When used together with: Netgear » Br500 » Version: N/A
Netgear » Ex6100v2 Firmware
Versions before (<) 1.0.1.98
cpe:2.3:o:netgear:ex6100v2_firmware:*:*:*:*:*:*:*:*
Matching versions
When used together with: Netgear » Ex6100v2 » Version: N/A
Netgear » Ex6150v2 Firmware
Versions before (<) 1.0.1.98
cpe:2.3:o:netgear:ex6150v2_firmware:*:*:*:*:*:*:*:*
Matching versions
When used together with: Netgear » Ex6150v2 » Version: N/A
Netgear » Ex6250 Firmware
Versions before (<) 1.0.0.134
cpe:2.3:o:netgear:ex6250_firmware:*:*:*:*:*:*:*:*
Matching versions
When used together with: Netgear » Ex6250 » Version: N/A
Netgear » Ex6400v2 Firmware
Versions before (<) 1.0.0.134
cpe:2.3:o:netgear:ex6400v2_firmware:*:*:*:*:*:*:*:*
Matching versions
When used together with: Netgear » Ex6400v2 » Version: N/A
Netgear » Ex6410 Firmware
Versions before (<) 1.0.0.134
cpe:2.3:o:netgear:ex6410_firmware:*:*:*:*:*:*:*:*
Matching versions
When used together with: Netgear » Ex6410 » Version: N/A
Netgear » Ex6420 Firmware
Versions before (<) 1.0.0.134
cpe:2.3:o:netgear:ex6420_firmware:*:*:*:*:*:*:*:*
Matching versions
When used together with: Netgear » Ex6420 » Version: N/A
Netgear » Ex7300v2 Firmware
Versions before (<) 1.0.0.134
cpe:2.3:o:netgear:ex7300v2_firmware:*:*:*:*:*:*:*:*
Matching versions
When used together with: Netgear » Ex7300v2 » Version: N/A
Netgear » Ex7320 Firmware
Versions before (<) 1.0.0.134
cpe:2.3:o:netgear:ex7320_firmware:*:*:*:*:*:*:*:*
Matching versions
When used together with: Netgear » Ex7320 » Version: N/A
Netgear » Ex7700 Firmware
Versions before (<) 1.0.0.216
cpe:2.3:o:netgear:ex7700_firmware:*:*:*:*:*:*:*:*
Matching versions
When used together with: Netgear » Ex7700 » Version: N/A
Netgear » Lbr20 Firmware
Versions before (<) 2.6.3.50
cpe:2.3:o:netgear:lbr20_firmware:*:*:*:*:*:*:*:*
Matching versions
When used together with: Netgear » Lbr20 » Version: N/A
Netgear » Rbk12 Firmware
Versions before (<) 2.7.2.104
cpe:2.3:o:netgear:rbk12_firmware:*:*:*:*:*:*:*:*
Matching versions
When used together with: Netgear » Rbk12 » Version: N/A
Netgear » Rbk13 Firmware
Versions before (<) 2.7.2.104
cpe:2.3:o:netgear:rbk13_firmware:*:*:*:*:*:*:*:*
Matching versions
When used together with: Netgear » Rbk13 » Version: N/A
Netgear » Rbk14 Firmware
Versions before (<) 2.7.2.104
cpe:2.3:o:netgear:rbk14_firmware:*:*:*:*:*:*:*:*
Matching versions
When used together with: Netgear » Rbk14 » Version: N/A
Netgear » Rbk15 Firmware
Versions before (<) 2.7.2.104
cpe:2.3:o:netgear:rbk15_firmware:*:*:*:*:*:*:*:*
Matching versions
When used together with: Netgear » Rbk15 » Version: N/A
Netgear » Rbk23 Firmware
Versions before (<) 2.7.2.104
cpe:2.3:o:netgear:rbk23_firmware:*:*:*:*:*:*:*:*
Matching versions
When used together with: Netgear » Rbk23 » Version: N/A
Netgear » Rbk43 Firmware
Versions before (<) 2.6.2.104
cpe:2.3:o:netgear:rbk43_firmware:*:*:*:*:*:*:*:*
Matching versions
When used together with: Netgear » Rbk43 » Version: N/A
Netgear » Rbk43s Firmware
Versions before (<) 2.6.2.104
cpe:2.3:o:netgear:rbk43s_firmware:*:*:*:*:*:*:*:*
Matching versions
When used together with: Netgear » Rbk43s » Version: N/A
Netgear » Rbk44 Firmware
Versions before (<) 2.6.2.104
cpe:2.3:o:netgear:rbk44_firmware:*:*:*:*:*:*:*:*
Matching versions
When used together with: Netgear » Rbk44 » Version: N/A
Netgear » Rbk53 Firmware
Versions before (<) 2.7.2.104
cpe:2.3:o:netgear:rbk53_firmware:*:*:*:*:*:*:*:*
Matching versions
When used together with: Netgear » Rbk53 » Version: N/A
Netgear » Rbr10 Firmware
Versions before (<) 2.6.2.104
cpe:2.3:o:netgear:rbr10_firmware:*:*:*:*:*:*:*:*
Matching versions
When used together with: Netgear » Rbr10 » Version: N/A
Netgear » Rbs10 Firmware
Versions before (<) 2.6.2.104
cpe:2.3:o:netgear:rbs10_firmware:*:*:*:*:*:*:*:*
Matching versions
When used together with: Netgear » Rbs10 » Version: N/A
Netgear » Rbs50y Firmware
Versions before (<) 2.6.2.104
cpe:2.3:o:netgear:rbs50y_firmware:*:*:*:*:*:*:*:*
Matching versions
When used together with: Netgear » Rbs50y » Version: N/A

Exploit prediction scoring system (EPSS) score for CVE-2021-27257

EPSS FAQ

0.18%

Probability of exploitation activity in the next 30 days EPSS Score History

~ 55 %

Percentile, the proportion of vulnerabilities that are scored at or less

CVSS scores for CVE-2021-27257

Base Score	Base Severity	CVSS Vector	Exploitability Score	Impact Score	Score Source
3.3	LOW	AV:A/AC:L/Au:N/C:N/I:P/A:N	6.5	2.9	NIST
Access Vector: Adjacent Network Access Complexity: Low Authentication: None Confidentiality Impact: None Integrity Impact: Partial Availability Impact: None
6.5	MEDIUM	CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N	2.8	3.6	Zero Day Initiative
Attack Vector: Adjacent Network Attack Complexity: Low Privileges Required: None User Interaction: None Scope: Unchanged Confidentiality: None Integrity: High Availability: None
6.5	MEDIUM	CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N	2.8	3.6	NIST
Attack Vector: Adjacent Network Attack Complexity: Low Privileges Required: None User Interaction: None Scope: Unchanged Confidentiality: None Integrity: High Availability: None

CWE ids for CVE-2021-27257

CWE-295 Improper Certificate Validation

The product does not validate, or incorrectly validates, a certificate.

Assigned by: zdi-disclosures@trendmicro.com (Primary)

References for CVE-2021-27257

https://www.zerodayinitiative.com/advisories/ZDI-21-264/

ZDI-21-264 | Zero Day Initiative
Third Party Advisory;VDB Entry
https://kb.netgear.com/000062883/Security-Advisory-for-Multiple-Vulnerabilities-on-Some-Routers-Satellites-and-Extenders

Security Advisory for Multiple Vulnerabilities on Some Routers, Satellites, and Extenders | Answer | NETGEAR Support
Patch;Vendor Advisory

CVEs referencing this url

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Vulnerability Details : CVE-2021-27257

Products affected by CVE-2021-27257

Exploit prediction scoring system (EPSS) score for CVE-2021-27257

CVSS scores for CVE-2021-27257

CWE ids for CVE-2021-27257

References for CVE-2021-27257