Security readout for executives and security teams
Plain-English summary
This is a critical router flaw in ASUS RT-AC68U Cloud Disk. A remote unauthenticated attacker could write arbitrary files through improperly controlled COPY and MOVE operations on vulnerable firmware before 3.0.0.4.386.41634. That creates serious integrity and availability risk for exposed devices.
Executive priority
Treat internet-exposed RT-AC68U routers as urgent. The issue is remotely reachable without authentication and can affect device integrity and availability. Prioritize firmware updates, exposure reduction, and replacement planning for unsupported devices.
Technical view
CVE-2021-37315 is an incorrect access control issue tied to improper sanitization of the source path for Cloud Disk COPY and MOVE operations. The CVSS 3.1 score is 9.1, network exploitable, low complexity, no privileges, no user interaction, with high integrity and availability impact.
Likely exposure
Exposure is likely limited to ASUS RT-AC68U routers running firmware before 3.0.0.4.386.41634 with Cloud Disk reachable. The CVE record’s affected vendor/product fields are incomplete, so confirm against asset inventory and ASUS firmware data.
Exploitation context
The source bundle does not show CISA KEV listing or active exploitation evidence. A public technical reference exists, but the provided CVE data supports arbitrary file write risk, not confirmed in-the-wild exploitation.
Researcher notes
The CVE maps to CWE-706 and describes unsafe handling of Cloud Disk COPY/MOVE source inputs. CVSS reports no direct confidentiality impact, but arbitrary file write can still support serious operational compromise. Product metadata in the CVE JSON is sparse.
Mitigation direction
- Upgrade RT-AC68U firmware to 3.0.0.4.386.41634 or later where available.
- Disable Cloud Disk if it is not required.
- Restrict router services from untrusted networks and the public internet.
- Check ASUS guidance for supported firmware and any compensating controls.
- Retire unsupported exposed devices if current firmware is unavailable.
Validation and detection
- Inventory ASUS RT-AC68U routers and record firmware versions.
- Verify whether Cloud Disk is enabled and externally reachable.
- Confirm vulnerable devices are upgraded or Cloud Disk is disabled.
- Review router logs and file storage for unexpected changes.
- Document exceptions and compensating controls for any device that cannot be updated.
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-706: 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-2021-37315 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
- 9.1 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/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.
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:N/UI:N/S:U/C:N/I:H/A:H3.95.2Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
9.1CriticalVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://robertchen.cc/blog/2021/03/31/asus-rceCVE reference
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 Incorrectly-Resolved Name or Reference
Use of Incorrectly-Resolved Name or Reference represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.