Analyst readout for executives and security teams
Plain-English summary
This is a critical router management flaw. A vulnerable Totolink A8000RU firmware build can let a remote attacker inject operating-system commands through the web management interface. Sources say public exploit details exist, but they do not show confirmed active exploitation or a vendor fix.
Executive priority
Treat this as urgent for any exposed affected router. Prioritize inventory and management-interface isolation before waiting for broader exploitation evidence.
Technical view
CVE-2026-9407 affects Totolink A8000RU firmware 7.1cu.643_b20200521. The setFirewallType function in /cgi-bin/cstecgi.cgi improperly handles the firewallType argument, leading to OS command injection. VulDB scores it CVSS 2.0 10.0 and describes remote, unauthenticated exploitability with public proof-of-concept availability.
Likely exposure
Exposure is likely limited to Totolink A8000RU devices running firmware 7.1cu.643_b20200521, especially where the web management interface is reachable from untrusted networks or the internet.
Exploitation context
The source bundle says exploit information has been publicly disclosed and may be used. KEV is false, and no cited source confirms active exploitation in the wild.
Researcher notes
Evidence supports command injection in cstecgi.cgi setFirewallType via firewallType, mapped to CWE-77 and CWE-78. Patch status is not provided in the sources, so remediation depends on vendor guidance or compensating controls.
Mitigation direction
- Identify Totolink A8000RU devices and firmware versions immediately.
- Restrict web management access to trusted admin networks or VPN only.
- Remove internet exposure for affected management interfaces.
- Check Totolink guidance for fixed firmware or official mitigation.
- Replace or isolate devices if no vendor fix is available.
Validation and detection
- Confirm whether A8000RU firmware 7.1cu.643_b20200521 is deployed.
- Verify management interfaces are not reachable from the internet.
- Review firewall rules limiting router administration access.
- Check logs for unusual requests to /cgi-bin/cstecgi.cgi.
- Track vendor and CVE sources for remediation updates.
Public sources used
Based on public source material and reviewed before publication.
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-77: 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 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-2026-9407 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
- 10 (2.0)
- Known Exploited
- No
- Published
Vector: AV:N/AC:L/Au:N/C:C/I:C/A:C/E:POC/RL:ND/RC:UR
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
4 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.
AV:N/AC:L/Au:N/C:C/I:C/A:C/E:POC/RL:ND/RC:UR 10 10 VulDB CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:P/RL:X/RC:R 3.9 5.9 VulDB CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:P/RL:X/RC:R 3.9 5.9 VulDB 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/E:P — — VulDB Vulnerability scoring details
Base CVSS 4.0 score
9.3 CriticalVector: 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/E:P
Base CVSS 3.1 score
9.8 CriticalVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:P/RL:X/RC:R
Base CVSS 3.0 score
9.8 CriticalVector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:P/RL:X/RC:R
Base CVSS 2.0 score
10 CriticalVector: AV:N/AC:L/Au:N/C:C/I:C/A:C/E:POC/RL:ND/RC:UR
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- Source timeline VulDB
Advisory disclosed
- Source timeline VulDB
VulDB entry created
- CVE reserved CVE Program
The CVE ID was reserved by the assigning CNA.
- Source timeline VulDB
VulDB entry last update
- CVE published CVE Program
The CVE record was published.
- CVE updated CVE Program
The CVE record metadata indicates this as the latest update time.
Source materials
- CVE List V5 source CVE List V5
- VDB-365388 | Totolink A8000RU Web Management cstecgi.cgi setFirewallType os command injection CVE reference, VulDB · vdb-entry, technical-description
- VDB-365388 | CTI Indicators (IOB, IOC, TTP, IOA) CVE reference, VulDB · signature, permissions-required
- Submit #813442 | Totolink A8000RU 7.1cu.643_b20200521 Command Injection CVE reference, VulDB · third-party-advisory
- https://github.com/Litengzheng/vuldb_new2/blob/main/A8000RU/vul_339/README.md CVE reference, VulDB · exploit
- https://www.totolink.net/ CVE reference, VulDB · product
Products and packages named in the record
CWE details
CWE links open conservative ATT&CK lookup hints, not official CWE-to-ATT&CK mappings. Source links are consolidated once in the official source material section above.