Security readout for executives and security teams
Plain-English summary
CVE-2026-1143 is a critical buffer overflow reported in TOTOLINK A3700R firmware 9.1.2u.5822_B20200513. A remote, authenticated attacker could potentially crash or take control of the device through the guest Wi-Fi configuration function. Public proof-of-concept exploit information is referenced, but KEV does not list active exploitation.
Executive priority
Prioritize within the normal emergency vulnerability process for exposed or business-critical routers. The public exploit reference and critical impact raise urgency, but there is no cited active exploitation and no confirmed patch information in the provided sources.
Technical view
The flaw affects setWiFiEasyGuestCfg in /cgi-bin/cstecgi.cgi. Manipulation of the ssid argument can trigger a buffer overflow, mapped to CWE-119 and CWE-120. The provided CVSS v2 vector is AV:N/AC:L/Au:S/C:C/I:C/A:C with score 9.0. Sources do not identify a vendor patch or fixed firmware version.
Likely exposure
Exposure is most relevant where TOTOLINK A3700R management interfaces are reachable by untrusted networks and running firmware 9.1.2u.5822_B20200513. The CVSS vector indicates authentication is required, but remote exploitation is possible once that condition is met.
Exploitation context
The source bundle states a public exploit exists and could be used for attacks. There is no KEV listing and no cited evidence of active exploitation. Treat reachable devices as high priority because router flaws can affect network control, traffic interception, and availability.
Researcher notes
Evidence is mainly from CVE and VulDB records plus a public PoC reference. The advisory names the vulnerable function and parameter but does not provide vendor remediation. Avoid assuming other TOTOLINK models or firmware versions are affected unless vendor or CVE sources later confirm it.
Mitigation direction
- Identify TOTOLINK A3700R devices and confirm firmware versions.
- Check TOTOLINK guidance for updated firmware or official workarounds.
- Restrict router administration access to trusted management networks only.
- Disable remote administration if not required by operations.
- Replace or isolate devices if no supported fix is available.
Validation and detection
- Inventory edge and branch networks for TOTOLINK A3700R devices.
- Verify whether firmware 9.1.2u.5822_B20200513 is present.
- Confirm management interfaces are not Internet-exposed.
- Review authentication and administrative access logs for unusual activity.
- Monitor vendor and CVE sources for patch or advisory updates.
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-119: 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-120: 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 lookupCVE-2026-1143 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 (2.0)
- Known Exploited
- No
- Published
Vector: AV:N/AC:L/Au:S/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
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.
AV:N/AC:L/Au:S/C:C/I:C/A:C/E:POC/RL:ND/RC:UR810Primary CVE scoreVulnerability scoring details
Base CVSS 2.0 score
9CriticalVector: AV:N/AC:L/Au:S/C:C/I:C/A:C/E:POC/RL:ND/RC:UR
Source materials
- CVE List V5 sourceCVE List V5
- VDB-341735 | TOTOLINK A3700R cstecgi.cgi setWiFiEasyGuestCfg buffer overflowCVE reference · vdb-entry, technical-description
- VDB-341735 | CTI Indicators (IOB, IOC, IOA)CVE reference · signature, permissions-required
- Submit #735502 | TOTOLINK A3700R V9.1.2u.5822_B20200513 Buffer OverflowCVE reference · third-party-advisory
- https://lavender-bicycle-a5a.notion.site/TOTOLINK-A3700R-setWiFiEasyGuestCfg-2e353a41781f8057a244ead07d5eaaff?source=copy_linkCVE reference · exploit
- https://www.totolink.net/CVE reference · product
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 Restriction of Operations within the Bounds of a Memory Buffer
Improper Restriction of Operations within the Bounds of a Memory Buffer represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.
Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
Buffer Copy without Checking Size of Input ('Classic Buffer Overflow') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.