CVE-2021-34947
CVE-2021-34947 is a high-severity vulnerability in Netgear D7800 Firmware with a CVSS 3.x base score of 8.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-787.
Key facts
- Severity: High (CVSS 3.x base score 8.8)
- EPSS exploit prediction: 1% (42nd percentile)
- Actively exploited: Not listed in CISA KEV
- EU (EUVD) id: EUVD-2021-21594
- Weakness: CWE-787
- Affected product: Netgear D7800 Firmware
- Published:
- Last modified:
Description
NETGEAR R7800 net-cgi Out-Of-Bounds Write Remote Code Execution Vulnerability. This vulnerability allows network-adjacent attackers to execute arbitrary code on affected installations of NETGEAR R7800 routers. Authentication is not required to exploit this vulnerability. The specific flaw exists within the parsing of the soap_block_table file. The issue results from the lack of proper validation of user-supplied data, which can result in a write past the end of an allocated data structure. An attacker can leverage this vulnerability to execute code in the context of root. . Was ZDI-CAN-13055.
Frequently asked questions
- What is CVE-2021-34947?
- NETGEAR R7800 net-cgi Out-Of-Bounds Write Remote Code Execution Vulnerability. This vulnerability allows network-adjacent attackers to execute arbitrary code on affected installations of NETGEAR R7800 routers. Authentication is not required to exploit this vulnerability. The specific flaw exists within the parsing of the soap_block_table file. The issue results from the lack of proper validation of user-supplied data, which can result in a write past the end of an allocated data structure. An attacker can leverage this vulnerability to execute code in the context of root. . Was ZDI-CAN-13055.
- How severe is CVE-2021-34947?
- CVE-2021-34947 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over an adjacent network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
- Is CVE-2021-34947 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (42nd percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2021-34947?
- CVE-2021-34947 primarily affects Netgear D7800 Firmware. In total, 41 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
- How do I fix CVE-2021-34947?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
- Does CVE-2021-34947 have an EU (EUVD) identifier?
- Yes. CVE-2021-34947 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2021-21594.
- When was CVE-2021-34947 published?
- CVE-2021-34947 was published on 2024-05-07 and last updated on 2026-06-17.
References
- https://kb.netgear.com/000064044/Security-Advisory-for-Pre-Authentication-Buffer-Overflow-on-Some-Routers-PSV-2021-0129
- https://www.zerodayinitiative.com/advisories/ZDI-21-1116/
Affected products (41)
- cpe:2.3:o:netgear:d7800_firmware:*:*:*:*:*:*:*:*
- cpe:2.3:o:netgear:ex2700_firmware:*:*:*:*:*:*:*:*
- cpe:2.3:o:netgear:ex6100_firmware:*:*:*:*:*:*:*:*
- cpe:2.3:o:netgear:ex6150_firmware:*:*:*:*:*:*:*:*
- cpe:2.3:o:netgear:ex6200_firmware:*:*:*:*:*:*:*:*
- cpe:2.3:o:netgear:ex6250_firmware:*:*:*:*:*:*:*:*
- cpe:2.3:o:netgear:ex6400_firmware:*:*:*:*:*:*:*:*
- cpe:2.3:o:netgear:ex6400v2_firmware:*:*:*:*:*:*:*:*
- cpe:2.3:o:netgear:ex6410_firmware:*:*:*:*:*:*:*:*
- cpe:2.3:o:netgear:ex6420_firmware:*:*:*:*:*:*:*:*
- cpe:2.3:o:netgear:ex6500v1_firmware:*:*:*:*:*:*:*:*
- cpe:2.3:o:netgear:ex7300_firmware:*:*:*:*:*:*:*:*
- cpe:2.3:o:netgear:ex7300v2_firmware:*:*:*:*:*:*:*:*
- cpe:2.3:o:netgear:ex7320_firmware:*:*:*:*:*:*:*:*
- cpe:2.3:o:netgear:ex7700_firmware:*:*:*:*:*:*:*:*
- cpe:2.3:o:netgear:ex8000_firmware:*:*:*:*:*:*:*:*
- cpe:2.3:o:netgear:lbr1020_firmware:*:*:*:*:*:*:*:*
- cpe:2.3:o:netgear:lbr20_firmware:*:*:*:*:*:*:*:*
- cpe:2.3:o:netgear:r6700ax_firmware:*:*:*:*:*:*:*:*
- cpe:2.3:o:netgear:r7800_firmware:*:*:*:*:*:*:*:*
- cpe:2.3:o:netgear:r8900_firmware:*:*:*:*:*:*:*:*
- cpe:2.3:o:netgear:r9000_firmware:*:*:*:*:*:*:*:*
- cpe:2.3:o:netgear:rax10_firmware:*:*:*:*:*:*:*:*
- cpe:2.3:o:netgear:rax120_firmware:*:*:*:*:*:*:*:*
- cpe:2.3:o:netgear:rax120v2_firmware:*:*:*:*:*:*:*:*
- cpe:2.3:o:netgear:rax70_firmware:*:*:*:*:*:*:*:*
- cpe:2.3:o:netgear:rax78_firmware:*:*:*:*:*:*:*:*
- cpe:2.3:o:netgear:rbr10_firmware:*:*:*:*:*:*:*:*
- cpe:2.3:o:netgear:rbr20_firmware:*:*:*:*:*:*:*:*
- cpe:2.3:o:netgear:rbr40_firmware:*:*:*:*:*:*:*:*
- cpe:2.3:o:netgear:rbr50_firmware:*:*:*:*:*:*:*:*
- cpe:2.3:o:netgear:rbs10_firmware:*:*:*:*:*:*:*:*
- cpe:2.3:o:netgear:rbs20_firmware:*:*:*:*:*:*:*:*
- cpe:2.3:o:netgear:rbs40_firmware:*:*:*:*:*:*:*:*
- cpe:2.3:o:netgear:rbs50_firmware:*:*:*:*:*:*:*:*
- cpe:2.3:o:netgear:rbs50y_firmware:*:*:*:*:*:*:*:*
- cpe:2.3:o:netgear:wn3000rpv2_firmware:*:*:*:*:*:*:*:*
- cpe:2.3:o:netgear:wnr2000v5_firmware:*:*:*:*:*:*:*:*
- cpe:2.3:o:netgear:xr450_firmware:*:*:*:*:*:*:*:*
- cpe:2.3:o:netgear:xr500_firmware:*:*:*:*:*:*:*:*
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