Security readout for executives and security teams
Plain-English summary
NETGEAR XR500 routers running firmware before 2.3.2.32 have an authentication bypass flaw. An attacker who can reach the device from an adjacent network could potentially bypass login protections and compromise confidentiality, integrity, and availability. This is high severity, but the supplied sources do not show confirmed active exploitation.
Executive priority
Treat as a high-priority network appliance issue where XR500 routers are deployed. Patch or replace affected devices promptly because successful bypass could allow serious compromise of router control and network traffic protections.
Technical view
CVE-2018-21118 affects NETGEAR XR500 devices before firmware 2.3.2.32. The CVSS 3.0 vector is AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H, indicating adjacent-network reachability, low attack complexity, no privileges, no user interaction, and high impact across CIA.
Likely exposure
Exposure is limited to NETGEAR XR500 devices running firmware earlier than 2.3.2.32. Risk is highest where untrusted users can access the same local or wireless network segment as the router or its management plane.
Exploitation context
The source bundle identifies authentication bypass and a high CVSS score. It does not include exploit details, public exploit confirmation, or CISA KEV listing. Do not assume internet-scale exploitation from these sources alone.
Researcher notes
Available evidence is sparse: the CVE record and NETGEAR advisory identify the affected model and fixed version, but not the bypass mechanism. Validation should focus on asset discovery, firmware state, and management-plane reachability rather than exploit reproduction.
Mitigation direction
- Inventory NETGEAR XR500 routers and record firmware versions.
- Update affected XR500 devices to firmware 2.3.2.32 or later.
- Review NETGEAR advisory for model-specific remediation guidance.
- Restrict router management access to trusted administrative networks.
- Replace unsupported or unpatchable devices.
Validation and detection
- Confirm whether any XR500 runs firmware earlier than 2.3.2.32.
- Verify management access is not reachable from untrusted network segments.
- Confirm firmware upgrade completion through the device administrative interface.
- Review router logs for unusual administrative access around the remediation window.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
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
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
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 lookupCVE-2018-21118 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 8.8 (3.0)
- Known Exploited
- No
- Published
Vector: CVSS:3.0/AC:L/AV:A/A:H/C:H/I:H/PR:N/S:U/UI:N
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.
CVSS vector scores
1 official scoreWe 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.
CVSS:3.0/AC:L/AV:A/A:H/C:H/I:H/PR:N/S:U/UI:N2.85.9Primary CVE scoreVulnerability scoring details
Base CVSS 3.0 score
8.8HighVector: CVSS:3.0/AC:L/AV:A/A:H/C:H/I:H/PR:N/S:U/UI:N
Source materials
- CVE List V5 sourceCVE List V5
- https://kb.netgear.com/000060240/Security-Advisory-for-Authentication-Bypass-on-XR500-PSV-2018-0324CVE reference · x_refsource_CONFIRM
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.