Security readout for executives and security teams
Plain-English summary
This affects a legacy Zyxel DSL customer-premises device. An attacker who can authenticate to the device could send a crafted web request and run operating system commands. Because CISA lists CVE-2024-40890 in KEV, organizations should treat exposed affected devices as urgent to find and remove or contain.
Executive priority
Treat this as urgent for asset owners managing legacy DSL equipment. The business risk is not broad software compromise, but unsupported network edge devices with known exploited command execution potential. Replace or contain affected devices promptly.
Technical view
CVE-2024-40890 is a post-authentication OS command injection flaw in the CGI program of Zyxel VMG4325-B10A firmware 1.00(AAFR.4)C0_20170615 and earlier. The CVSS 3.1 score is 8.8 with network access, low complexity, low privileges, no user interaction, and high confidentiality, integrity, and availability impact.
Likely exposure
Exposure is most likely where legacy Zyxel VMG4325-B10A DSL CPE remains deployed, especially if device administration is reachable over a network path available to attackers. The source bundle marks other versions as unaffected by default, but evidence is limited to the listed product and firmware.
Exploitation context
Active exploitation is supported by the CISA KEV reference in the source bundle. Public details provided here do not include exploit steps, targeting scale, or observed attacker behavior. The vulnerability requires authentication, but successful abuse could give OS command execution on the device.
Researcher notes
The provided evidence supports one affected legacy product and firmware line, CWE-78, post-authentication HTTP POST attack surface, CVSS 8.8, and CISA KEV inclusion. It does not provide patch availability, exploit mechanics, IoCs, or broader affected product claims.
Mitigation direction
- Inventory Zyxel VMG4325-B10A devices and record firmware versions.
- Prioritize replacement or removal of unsupported affected firmware.
- Check Zyxel advisory for any model-specific vendor guidance.
- Restrict administrative access to trusted management networks only.
- Review and harden device credentials where these devices remain temporarily.
- Monitor affected device logs for suspicious administrative activity.
Validation and detection
- Confirm whether any VMG4325-B10A devices exist in the environment.
- Compare firmware to 1.00(AAFR.4)C0_20170615 or earlier.
- Verify administrative interfaces are not internet-exposed.
- Check asset records for unsupported DSL CPE still in service.
- Review CISA KEV status in vulnerability prioritization workflows.
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.
CWE-78: Command execution behavior lookup
Command injection weaknesses can lead defenders to review execution techniques and command interpreter telemetry. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupExecution behavior lookup
The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2024-40890 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 (3.1)
- Known Exploited
- Yes
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
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.
CISA KEV status
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:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H2.85.9Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
8.8HighVector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-command-injection-and-insecure-default-credentials-vulnerabilities-in-certain-legacy-dsl-cpe-02-04-2025CVE reference · vendor-advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2024-40890CVE reference · government-resource
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.
Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.