Security readout for executives and security teams
Plain-English summary
Affected routers and embedded networking devices can be taken over remotely without credentials when their infosrvd service is reachable over UDP port 9992. Successful exploitation provides root-level command execution, allowing attackers to steal information, alter configurations, disrupt service, or use the device as an internal foothold.
Executive priority
Act immediately on confirmed affected devices, prioritizing internet-facing and business-critical locations. Root-level, unauthenticated compromise creates material operational and data risk. Because the sources name no patch, require rapid exposure reduction, vendor confirmation, compromise review, and replacement planning where support is unavailable.
Technical view
CVE-2026-74233 is an unauthenticated OS command injection in MQWrt infosrvd. Crafted UDP traffic to port 9992 can execute arbitrary commands as root. Authentication is ineffective because it relies on a hardcoded salt and accepts an all-zero wildcard MAC. CVSS 3.1 is 9.8, reflecting network reachability and complete confidentiality, integrity, and availability impact.
Likely exposure
Exposure is highest where a listed device and firmware version permits UDP/9992 from the internet, guest networks, or other untrusted segments. Internally reachable devices remain vulnerable to compromised hosts. The bundle does not establish whether infosrvd is enabled or externally exposed by default.
Exploitation context
The vulnerability requires no credentials, privileges, or user interaction and has low stated attack complexity. The supplied record is not marked as CISA KEV, and the cited source bundle does not establish active exploitation. Treat scanning or unexpected UDP/9992 traffic as suspicious, but not proof of compromise.
Researcher notes
Affected versions vary by model; several devices have an unknown vendor in the record, and default affected status is unknown. Confirm model and firmware rather than extrapolating to other releases. The source bundle attributes both command injection and broken authentication design, but provides no vendor fix, deployment-default, or observed-exploitation evidence.
Mitigation direction
- Block untrusted inbound and lateral UDP/9992 traffic immediately.
- Isolate affected devices from sensitive systems and management networks.
- Check Zbtlink or device-reseller guidance for corrected firmware; no patch is identified in the sources.
- Replace or retire affected devices if supported remediation is unavailable.
- Monitor affected segments for unusual UDP/9992 traffic and post-exploitation activity.
Validation and detection
- Inventory listed models and confirm their installed firmware versions.
- Determine whether infosrvd is running and reachable over UDP/9992 from each network zone.
- Review firewall, flow, and device logs for unexpected UDP/9992 sources.
- Check device configurations, accounts, processes, and outbound connections for unauthorized changes.
- After remediation, confirm UDP/9992 is inaccessible from untrusted and unnecessary internal networks.
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-321: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. 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 lookupCWE-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-2026-74233 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
- Critical
- CVSS
- 9.8 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/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.
SSVC decision data
CVSS vector scores
2 official scoresWe 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:N/UI:N/S:U/C:H/I:H/A:H3.95.9VulnCheckCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N——VulnCheckVulnerability scoring details
Base CVSS 4.0 score
9.3CriticalVector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
Base CVSS 3.1 score
9.8CriticalVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
Source materials
- CVE List V5 sourceCVE List V5
- https://www.vulncheck.com/advisories/zbtlink-mqwrt-infosrvd-command-injectionCVE reference, VulnCheck · third-party-advisory
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.
Use of Hard-coded Cryptographic Key
Use of Hard-coded Cryptographic Key represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.
Improper Neutralization of Special Elements used in an OS Command
Improper Neutralization of Special Elements used in an OS Command represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.