NETGEAR Multiple Routers httpd Stack-based Buffer Overflow Remote Code Execution Vulnerability

published 2024-05-07 2 y ago modified 2026-06-17 4 mo ago also EUVD-2021-21629

cvss: 8.8; version 3.0, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.6%; EPSS 0.6% chance of exploitation in 30 days, percentile 48%
public exploits: 0; none known

NETGEAR Multiple Routers httpd Stack-based Buffer Overflow Remote Code Execution Vulnerability. This vulnerability allows network-adjacent attackers to execute arbitrary code on affected installations of multiple NETGEAR routers. Authentication is not required to exploit this vulnerability.

The specific flaw exists within the httpd service, which listens on TCP port 80 by default. When parsing the strings file, the process does not properly validate the length of user-supplied data prior to copying it to a fixed-length stack-based buffer. An attacker can leverage this vulnerability to execute code in the context of root.

. Was ZDI-CAN-13709.

Patch / fix

fixed in 20

netgear dc112a_firmware 1.0.0.62
netgear ex3700_firmware 1.0.0.94
netgear ex3800_firmware 1.0.0.94
netgear ex6120_firmware 1.0.0.66
netgear ex6130_firmware 1.0.0.46
netgear ex7000_firmware 1.0.1.106
netgear ex7500_firmware 1.0.1.76
netgear mr60_firmware 1.1.6.122
netgear mr80_firmware 1.1.6.10
netgear ms60_firmware 1.1.6.122
netgear ms80_firmware 1.1.6.10
netgear lax20_firmware 1.1.6.30
netgear r6400_firmware 1.0.1.76
netgear r6400v2_firmware 1.0.4.120
netgear r6700v3_firmware 1.0.4.120
netgear r6900p_firmware 1.3.3.148
netgear r7000_firmware 1.0.11.128
netgear r7000p_firmware 1.3.3.148
netgear r7100lg_firmware 1.0.0.72
netgear r7850_firmware 1.0.5.76

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: total
Assessed: 2 y ago (2024-05-08)

Exploit prediction

0.58% chance of exploitation in the next 30 days, higher than 48% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.0	8.8	CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected products

NETGEAR Multiple Routers
netgear multiple_router_firmware

Classification

Weakness

CWE-121 Stack-based Buffer Overflow
CWE-787 Out-of-bounds Write

References

kb.netgear.com /000064313/Security-Advisory-for-Pre-Authentication-Buffer-Overflow-on-Some-Extenders-Routers-and-DSL-Modem-Ro
vendor-advisory
zerodayinitiative.com /advisories/ZDI-21-1274/
third-party-advisory

Sources

CVE List CVE-2021-34982
NVD CVE-2021-34982

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary