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CVE Record

CVE-2021-35973: NETGEAR WAC104 devices before 1.0.4.15 are affected by an authentication bypass vulnerability in /usr/sbin/...

NETGEAR WAC104 devices before 1.0.4.15 are affected by an authentication bypass vulnerability in /usr/sbin/mini_httpd, allowing an unauthenticated attacker to invoke any action by adding the &currentsetting.htm substring to the HTTP query, a related issue to CVE-2020-27866. This directly allows the attacker to change the web UI password, and eventually to enable debug mode (telnetd) and gain a shell on the device as the admin limited-user account (however, escalation to root is simple because of weak permissions on the /etc/ directory).

CriticalCVSS 9.8Not KEV-listedUpdated
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Glexia's TakeAutomated analysiscritical

Security readout for executives and security teams

Plain-English summary

CVE-2021-35973 lets an unauthenticated attacker bypass the NETGEAR WAC104 web interface protections on firmware before 1.0.4.15. The reported impact includes changing the web UI password, enabling debug access, and reaching a shell. Treat exposed or unpatched devices as urgent infrastructure risk.

Executive priority

Prioritize remediation where WAC104 management interfaces are internet-facing or reachable from broad internal networks. The business concern is loss of device control and possible pivot risk, not just configuration tampering.

Technical view

The issue is an authentication bypass in the WAC104 mini_httpd component. The CVE description states unauthenticated HTTP requests can invoke protected actions and may lead from admin interface control to shell access, with simple root escalation due to weak /etc permissions. Affected firmware is before 1.0.4.15.

Likely exposure

Exposure is limited to NETGEAR WAC104 access points running firmware before 1.0.4.15, especially where the management web interface is reachable from untrusted networks.

Exploitation context

The source bundle does not show CISA KEV listing or confirmed active exploitation. However, the public technical write-up and CVE description provide enough detail to make exposed vulnerable devices high risk.

Researcher notes

Evidence comes from the CVE record, NETGEAR advisory, and a public researcher write-up. The bundle names WAC104 before 1.0.4.15 only; do not generalize to other NETGEAR models without separate evidence.

Mitigation direction

  • Upgrade NETGEAR WAC104 firmware to 1.0.4.15 or later per NETGEAR guidance.
  • Restrict the management interface to trusted admin networks or VPN access.
  • Disable unnecessary remote administration exposure.
  • Rotate web UI credentials after updating, especially if exposure existed.
  • Inspect device configuration for unexpected debug or remote access changes.

Validation and detection

  • Inventory NETGEAR WAC104 devices and record firmware versions.
  • Confirm no WAC104 is running firmware earlier than 1.0.4.15.
  • Review network exposure of the web management interface.
  • Check device settings for unexpected password, debug, or telnet changes.
  • Use vendor advisory details to verify the applied firmware version.
Prepared
Confidence
high
Sources
4

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

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description · low confidence lookup

Credential and access behavior lookup

The CVE wording references authentication or credential exposure, so valid-account and credential-access review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.

Open ATT&CK lookup
cve · low confidence lookup

CVE-2021-35973 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

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Vulnerability profileCVE Program record
Severity
Critical
CVSS
9.8 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AC:L/AV:N/A:H/C:H/I:H/PR:N/S:U/UI:N

Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

1CVSS vectors
0Timeline events
0ADP providers
3Source links

CVSS vector scores

1 official score

We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.

ScoreVersionSeverityVectorExploitImpactSource
9.8CVSS 3.1CriticalCVSS:3.1/AC:L/AV:N/A:H/C:H/I:H/PR:N/S:U/UI:N3.95.9Primary CVE score

Vulnerability scoring details

Base CVSS 3.1 score

9.8Critical
CVSS 3.1 vector shape for CVE-2021-35973Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AC:L/AV:N/A:H/C:H/I:H/PR:N/S:U/UI:N

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
HighLowNone

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
n/an/an/aListed
Weakness

CWE details

No CWE listed

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.