CVE-2021-31802
CVE-2021-31802 is a high-severity vulnerability in Netgear R7000 Firmware with a CVSS 3.x base score of 8.8. Its EPSS exploit-prediction score of 14% places it in the 96th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-787.
Key facts
- Severity: High (CVSS 3.x base score 8.8)
- CVSS v2: 8.3
- EPSS exploit prediction: 14% (96th percentile)
- Actively exploited: Not listed in CISA KEV
- Weakness: CWE-787
- Affected product: Netgear R7000 Firmware
- Published:
- Last modified:
Description
NETGEAR R7000 1.0.11.116 devices have a heap-based Buffer Overflow that is exploitable from the local network without authentication. The vulnerability exists within the handling of an HTTP request. An attacker can leverage this to execute code as root. The problem is that a user-provided length value is trusted during a backup.cgi file upload. The attacker must add a \n before the Content-Length header.
Frequently asked questions
- What is CVE-2021-31802?
- NETGEAR R7000 1.0.11.116 devices have a heap-based Buffer Overflow that is exploitable from the local network without authentication. The vulnerability exists within the handling of an HTTP request. An attacker can leverage this to execute code as root. The problem is that a user-provided length value is trusted during a backup.cgi file upload. The attacker must add a \n before the Content-Length header.
- How severe is CVE-2021-31802?
- CVE-2021-31802 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-2021-31802 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 14% (96th percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2021-31802?
- CVE-2021-31802 affects Netgear R7000 Firmware. See the affected-products list for the exact vulnerable versions.
- How do I fix CVE-2021-31802?
- 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.
- When was CVE-2021-31802 published?
- CVE-2021-31802 was published on 2021-04-26 and last updated on 2026-06-17.
References
- https://ssd-disclosure.com/ssd-advisory-netgear-nighthawk-r7000-httpd-preauth-rce/
- https://www.netgear.com/about/security/
Affected products (1)
- cpe:2.3:o:netgear:r7000_firmware:*:*:*:*:*:*:*:*
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