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Public proof of concept

CVE-2021-31802

A public proof of concept exists; no exploitation attested.

  • Published2021-04-26
  • WeaknessCWE-787

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

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.

Timeline

dates in UTC
  1. 2021-04-2613:15CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-11-04 09:37 UTC
Indicators tagged with this CVE, per day0 indicators over 7 days
Block these indicators
  • Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2021-31802?format=txt
  • CSV export: https://api.ismalicious.com/edl/cve/CVE-2021-31802?format=csv
  • TAXII collection of exploited CVEs
  • The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD
Netgear r7000 firmwareversion to verify
BranchAffectedFixed in
1.0≤ 1.0.11.116no fix published

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Fix

Advisories and patches

Detection

Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof-of-concept repositories
none listed
PoC-in-GitHub
Metasploit modules
1 moduleauxiliary/admin/http/netgear_r7000_backup_cgi_heap_overflow_rcerank: normalModule metadata: Metasploit Framework, © Rapid7, Inc., BSD-3-Clause.
Metasploit Framework

Sources

  • NVDCVSS 3.18.8read 2026-10-23
  • NVDCVSS 2.08.3read 2026-10-23
  • NVDweakness (CWE)CWE-787read 2026-10-23
  • FIRST EPSSEPSS score14.2 %read 2026-11-03
  • Metasploit FrameworkMetasploit modules1known since 2026-11-01

Identifiers

Technical details

CVSS v3 Vector
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Published
2021-04-26
Last Modified
2026-06-17
NVD status
Modified

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.

Is CVE-2021-31802 actively exploited?

Active exploitation of CVE-2021-31802 has not been confirmed. Its EPSS score was 14.2% on 2026-11-03, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2021-31802?

CVE-2021-31802 has a CVSS v3 base score of 8.8 (HIGH severity), with vector string CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

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Sources for this record