CVE-2021-37315Public exploitNetwork attack vector

Unauthenticated file writes via unsanitized WebDAV sources

Published Feb 3, 2023 · Updated Mar 26, 2025

Incorrect access control in ASUS RT-AC68U Cloud Disk firmware before 3.0.0.4.386.41634 allows remote attackers to write arbitrary files. The mod_webdav COPY and MOVE handlers fail to require the resolved source path to begin with /mnt, allowing preexisting router files to populate attacker-chosen paths beneath /mnt. Cloud Disk must be enabled, and the write primitive controls file placement and structure rather than file contents.

CVSS severity9.1
Critical
EPSS probability1.11%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Incorrect access control in ASUS RT-AC68U Cloud Disk firmware before 3.0.0.4.386.41634 allows remote attackers to write arbitrary files. The mod_webdav COPY and MOVE handlers fail to require the resolved source path to begin with /mnt, allowing preexisting router files to populate attacker-chosen paths beneath /mnt. Cloud Disk must be enabled, and the write primitive controls file placement and structure rather than file contents.

The record

CVE
CVE-2021-37315
Published
Feb 3, 2023
Updated
Mar 26, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-706, T1565.001
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 3, 2023CVE publishedPublication date reported by the CVE source.
  2. Mar 26, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

9.1CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H
9.1NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-706Use of Incorrectly-Resolved Name or Reference
T1565.001Stored Data Manipulation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo